No, it really doesn't beg the question but then I guess you'd have to know what begging the question actually means.
However I could ask you a similar question. Looking at what you post in this thread, most of it is negative and snarky. If you think so much of the superhero based entertainment, on both big and small screens, is derisible then why bother watching any of it? If 99% of it is terrible or at least disappointing, then armed with that knowledge surely only a total lunatic would watch any superhero based movie or TV show.
Based on your "logic" nobody should watch Supergirl, Gotham, iZombie, Lucifer, Preacher, Blackbirds or even Teen Titans Go! because they don't link to a pair of TV shows on what is a fairly small network.
If they're pumping it up the way Arrow and Flash have been, and it's supposed to be on the same network (I welcome correction if I'm wrong), to forsake such an opportunity to have that connection between 3 shows (not even Marvel has done that directly yet, since nobody from Agents of SHIELD or Agent Carter appeared in Daredevil) is such a waste. If they're going totally bubbly and goofy with it they could at least leave it open for appearances by more characters to give it a good way to move in a different direction if audiences don't like it, to help keep it from getting cancelled if they really want it to last more than 1/2-1 season.
People didn't generally warm up to Andrew Garfield's awkward nerdy Peter Parker and I see Kara/Supergirl being looked at in the same way except that she'd probably also get feminists on her case too. It's been pretty elephant-in-the-room-y that DC is trying to go through every Marvel book to see what works and play catch-up but they don't have a good eye for what works and what doesn't.
As for the rest of those things, I won't watch Gotham because there's no Batman, I've never read iZombie so I have no opinion one way or another, same with Lucifer/Blackbirds, I enjoy Teen Titans because the intent to be goofy is implied in the fact that it's a really primitively animated cartoon, and while I loved the Preacher graphic novels, I am just a bit skeptical about some of the casting choices. With Supergirl, the entire tone of the show seems not to really mesh with a winning formula. I don't have anything against them trying something new, but to just jump out of the plane with no parachute just doesn't make sense. I suppose if it gets cancelled after 6 episodes it won't matter much but I just hate to see a waste of such potential.
I love the idea of superhero shows and movies but as a fan I'd just like them done right and it so rarely happens that it tends to get a bit disappointing. All I can do is continue to shell out the cash for tickets and hope that them making all kinds of money encourages them (all of them, Marvel, DC and others) to either continue doing well, or do better. The fact that trivial decisions that could be made by teenagers seem beyond the imagination of studio execs so much of the time does inspire some bitterness though, that I can't lie about.