The showrunner openly stated that he added Isis as a main character to spite Trump, because you know Trump, in his fucking 70s, and the leader of the free world, is really into the fucking CW live action adaptations DC Universe. I'm sure he was just fucking fuming over Isis.
I do find it hilarious how they called a muslim character Isis. Also, they made her muslim even though her powers come from the fucking Egyptian Gods, so she knows for a fact that Islam is wrong and she should be worshiping Ra or whatever. Then for no reason they made her from the future, so they could say she was from a dystopian world where "religion" is banned, because they didn't have the balls to come out and say they just hate christians, so instead I'm supposed to be really afraid of those right-wing atheists taking over, as if it wouldn't be the left that would try to institute a ban on religion. Of course, even if they did, they'd exempt islam (and judaism), or outright force people to convert to it.
But Isis wasn't even what made me give up. It was the episode where they met Helen of Troy, and the whole thing was an excuse for a GRILL POWER episode. First of all, out of all the DCU shit they could be doing, I don't want to see an episode wasted on something like Helen of Troy. But okay, the most beautiful woman alive is so beautiful that she makes men act irrationally like they're hypnotized or whatever. Fine. The main character of the show, another OC that I actually tolerated, is a lesbian. If she was also affected by Helen of Troy, that might actually be interesting, not only because of actually utilizing the fact that she's a lesbian for a plot where it would actually be relevant and not just tacked on for points, but also because it would clash more with her no-nonsense attitude than it would with the buffoons that are all the men in the series. But nope. She's immune for no reason and they just don't reference it. There were several other episodes in the season before that that already sucked, but for some reason that was the one that made me realize I just needed to give up on the whole universe.
Real shame, too, because their version of The Legion of Doom in Season 2 was actually pretty cool, even if it was really just Reverse Flash carrying the entire premise.
The CW writers clearly have no respect for comic books or sci-fi in general. They don't take the premises seriously because they'd rather be writing for Gossip Girl or whatever the equivalent is these days, because clearly those are much better, more serious shows, because superheroes are silly. I mean, he runs fast? Really?
They don't care enough to read the comics and see that, with Flash in particular, the sci-fi is a key element. He's known for "Flash Facts," where he (the writer) tries to explain how the things that happen in his stories are based in actual scientific principle. But the dumb women and soyboys at CW don't like science fiction, they "love the science," so they just treat "science" like magic, and handwave everything with "technobabble," not realizing that the sci-fi they think they're referencing by using "technobabble" tried to minimize how much they did it, and also tried to make it internally consistent. This is notably the same reason the same types of writers have ruined things like Star Trek, which the writers of The Flash are probably more familiar with than they are with Flash comics. Which is to say they obviously aren't at all familiar with either, but especially not Flash comics.
Even when I liked the actual plot of the overall season, in Season 2, clearly what happened is Geoff Johns (or someone like that), who actually had knowledge of the comics, and gave a shit about actually utilizing the same basic types of plots and characters that you might see in the comics, came in and laid down an actually clever plot for the overall season. Then the individual writers came in to do the individual episodes, and they fucked up like they usually do, in all the same ways, but at least the overall season arc carried it.
The same thing happened on the later seasons of Smallville, where clearly there was like one guy on the writing staff who actually gave a shit about Superman or ever read a comic in his life, while everyone else was just trying to write The OC or whatever. Also sometimes Geoff Johns would come in and write a special episode, which was usually extra important to the season arc, and that carried everything. In that case, the one writer who gave a shit was probably Brian K. Vaughan, since he wrote the Smallville Season 11 Comics, which were actually great, and had all the good trends from the show with none of the bad. Also the whole show in general was more tolerable because SJWism wasn't as bad/powerful as it got in the following decade.
tl;dr: The writers don't respect the source material, and that's gotten worse over time. They used to just be women and soyboys that wanted to write teen dramas and thought comics and sci-fi were dumb. Now they're women and soyboys that want to write outright propaganda, and think comics and sci-fi are evil.