Both have "Strong Female Characters," but is that actually the reason? Not really. Both failed from a failure to act.
If we're all being honest here, Agent Carter's season 1 should have killed it. At worst, women were ignored in the late 40s, not belittled and treated like crap. Almost everyone in her entire office outright hated her. Seriously, how did any of these guys ever have dates with attitudes like that? Carter, in turn, was so hostile to every single male in the office it was grating (hate the people who hate her? Fine. Hate the people who are NICE to her? WTF lady?). By the end of the first season, it had been toned down. And Season 2 almost turned that off completely, which was nice ... then it went soapy with the villains, and finally just went bizarre with a ten minute musical number in one of the last few episodes ... a musical number that came out of nowhere THAT HAD NOTHING TO DO WITH THE REST OF THE STORY.
So, no, while it's better than Agents of Stupid, I will not really miss the show. Then again, who'll miss it? It's already got a petition to make it a NetFlix show with fifty thousand names on it. Yes. Really. Maybe then they'll cut back on the ultra-hard "Men are evil, womyn rules" bit entirely, cut out the soap opera, and just stick with halfway decent writing.
At the end of the day, Agent Carter didn't fail because the character wasn't strong enough, or even too strong.
The writing sucked.
Even the good season, number 2, was padded with irrelevant, unnecessary flashbacks that felt like an Arrow knockoff. I didn't care about the crazy super villain going from her politician husband to her gangster boyfriend. I didn't care about the pseudo-Illuminati (Seriously? Evil Businessmen rule the world? What is this? The 90s? Why not have evil white supremacist militias, too?).
Perhaps the writers felt that the character could carry the program. It might have happened if the show had actually spent more time with her. The show is called Agent Carter, not "Super-powered Criminal Minds."
And it was an utter train wreck, a puff piece of a TV show filled with more cotton candy than a carnival. The characters were very ... chick flick. And no, not a good or witty chick flick (yes, those exist), but bad ones, with all the cliches. You know the ones I'm talking about: eating ice cream with her sister on a couch, talking out her feelings with her friends, and where her true "strength" isn't that she can lift a building, but that's she caring, compassionate and understanding. Are all of these automatically a problem? Not really. The Flash and Arrow also lean heavily on emotional stability, even angst. But the CW programs breaks up these thoughtful moments about our characters' emotional lives with at least four fight scenes an episode, a puzzle to solve, and threats to people we care about.
But for Supergirl, the writers relied on these moments. The better episodes had all of the latter elements. Their episode with a nuclear-powered psychopath hunting Cat Grant, and they had to figure out who the bad guy was, what his motivations were, and how to actually beat him? Those parts were fun, weren't they?
Then there's 15 minutes of Kara whining that Jimmy Olsen called in Superman to save her when it clearly looked like she was getting her ass kicked. Then she had to apologize for whining. Wasn't that fun? No? Yeah, you're not alone. That was so much of the series, it was painful.
What went wrong? Why did a team that puts out a product of quality put out this level of drek?
To start with, Supergirl was originally a project meant for the CW. But CBS wanted it, and obviously wanted it for their targeted audience -- really stupid ten year old girls who didn't know any better, and SJWs who felt like they could pat themselves on the back about such a strooooonnnnggg woman role model. Granted, on Supergirl, there are a lot of moments I can see a good script struggling to get through.
It's one of those moments where I can almost see studio interference doodling on the script pages in crayon. Every time that the show looks like it's going to be awesome, it starts whining.
And Supergirl is budgeted at $3 million an episode? Where'd that money go? Calista Flockhart's salary and hair care? They have THREE major sets -- a bat cave that looks less impressive than Arrow's, an office set, and a spaceship that is only a black room with a CGI table. Are they telling me that it costs $3 million for special effects that aren't much better than the ones Christopher Reeves had? Or was it all because it was shot in LA, and not the cheaper Vancouver of the other Berlanti-verse shows.
I'm figuring the move to the CW could be a vast improvement. Especially if they do something simple and merge the universes. No, I'm not suggestion a four-part crossover even that ends with Supergirl coming to the same universe as the other three shows ... that could be a bit of a Crisis in and of itself. Heh.
Besides, I'm trying to imagine Kara meeting .... anyone on Arrow, really. "Hi, meet Oliver .... no, perhaps Thea .... er, um, Felicity. That's safe. Except Felicity is just like Kara, only without superpowers."
That would be amusing.
At the end of the day, why did these shows fail? You could say that it was political -- you know, writers or studios pushing an agenda. Though I'm not even entirely certain that they know what their agenda was? Was it Grrrl power? In which case, I can recommend a webcomic for you. Was it men are evil? Well, then, it would be strange, since Kara lusted after photographer and part time underwear model Jimmy Olsen, while Agent Carter didn't know what she wanted in her convoluted love life.
So, while it may in part be that CBS wanted a role model for ten year old girls and TrigglyPuff, the simple version is that there wasn't any "there" there. There was no substance, and barely any style. You know you have to worry when one of the most interesting characters on the show was their low-rent Lex Luthor, played by objectivist Maxwell Lord. Hell, I spent the last two episodes screaming at the television for them to stop talking at each other and JUST DO SOMETHING DAMNIT. And while Agent Carter didn't suffer as much from the problem, there was a lot of uneven writing, where they didn't know if they wanted a spy thriller, or if they wanted a soap opera. They tried for both, and got neither. Seriously, when the most interesting character on the show, with the most character development, is Jarvis, not Agent Carter, in the words of Oliver Queen, you have failed this series.
But, again, in the case of Supergirl, I still hold out hope. With the move to Vancouver, expect to see the end of Calista Flockhart, and probably a few of the other actors, who would rather not move to the frozen north. They would rather stay in Hell-A, along with the CBS studio execs who scribbled notes all over the scripts.
And the advantage of being on the CW? Look over the writers of The Flash and Arrow. You might recognize some names. They're comic book writers, like Geoff Johns, or Paul Dini (of the cartoon Batman from the early 90s). And you won't see them on Agent Carter or on Supergirl.
First rule of writing for a comic book show? You might want to know something about comic books.