I don't think it's about tolerance of free speech here. It's not a free speech issue. It's about using a superhero show as a political forum, which is inappropriate and disrespectful to the audience.
You're blatantly contradicting yourself. It absolutely
is a free speech issue if you object to a fictional work's right to express speech that you don't personally agree with. Tell me: Would you have the same objection to a superhero show advancing a conservative viewpoint?
And as I said, superhero fiction has always, always been political. Even the supposedly fluffy
Batman '66 did a scathing satire of the political process in "Hizzoner the Penguin"/"Dizzoner the Penguin." And a lot of its commentary is still surprisingly relevant 50 years later.
Heck, even stories in which superheroes just blandly defend the status quo are making the political statement that the status quo is all right the way it is. Like another
Batman '66 episode, "Nora Clavicle and the Ladies' Crime Club," which was a profoundly sexist mockery of the whole idea of feminism and women's rights.
As for the comics getting political, that's more of a recent thing as again, the liberal writers took over from the people that made the characters loved in the first place. It turned me off of comic books.
Again, the people who originally created these characters back in the '30s and '40s were mostly from Jewish immigrant families -- people who were routinely treated the same way Muslim and Mexican immigrants are treated by many Americans today. They were outsiders themselves, victims of nationalist and religious bigotry, and they grew up in poverty. Their superhero creations thus tended to be quite activist and leftist. The post-WWII Superman radio show was so emphatically liberal and pedantically pro-social justice that it makes today's
Supergirl seem moderate and understated. Marvel and DC Comics in the '70s both pushed hard to be socially relevant and progressive; Marvel broke ground with black heroes like Black Panther and the Falcon, and DC got heroes like Green Lantern and Green Arrow involved in social causes -- although the unpowered Wonder Woman of the early '70s tended somewhat more toward the right in at least some ways, taking a rather aggressive stance in a story about the Vietnam conflict and even expressing skepticism toward the feminism that the character had originally been created to advocate.