[MENTION=13244]Tom[/MENTION], I hear you man. I think the discussion really just comes down to context of what each stable is trying to and can achieve within their circumstances. What Marvel is doing works well because if you look at the properties they've chosen for the Netflix extension of their cinematic universe, you'll note an interesting pattern. Daredevil, Jessica Jones, Luke Cage, Iron Fist... These are ideally characters who are truly known to interact with the main Avengers as far as the mainstream audience is concerned (comics might beg to differ but the cinematic universe set their own precedent here). And on top of that, they aren't actually really known by the general public, apart from the comic book fans in the know. This in itself gave them more leeway to be creative with a sub-universe that actually feels somewhat self contained with characters and narratives that are unknown to the general audience while being a part of the larger universe, yet will garner interest from fans purely because of the consistency of the quality output of the Marvel brand.
The DC brand doesn't have as consistent a track record as Marvel's brand, which means their choices have to be based on a different philosophy. They can't put someone Constantine on TV expect to get real interests (they did that and the show was decent but it didn't garner interest). So what do they do? Take characters that might not be the heavy weights of their character line up, but the general public has somewhat more of an awareness of them. Green Arrow, The Flash (an actual DC heavy weight), Supergirl. These are characters the average audience might not know as well as the big names (barring Flash), but they definitely are more aware of them than the Marvel choices, and that's the decision DC had to make to garner interest in the TV realm. Great, so now we've got the makings of a successful TV extension to the DC Universe (with Man of Steel already counted as a success in being the first stepping stone of their universe, however divisive it is). So what's the problem? Well, for one, the choices they had to make with lesser known yet known properties presents problems with tying things together. The Marvel cinematic universe doesn't constrict the Netflix universe even if they're simply because they can tell stories that don't call for Daredevil, Jessica Jones, etc to show up in The Avengers movies and vice versa, while Supergirl immediately brings up Superman in public mind (her stories would have to staunchly give some deference to Man of Steel), Green Arrow is actually a JL member in a lot of JL incarnations, The Flash (well, I needn't go into his case). Vice versa, does Supes show up on Supergirl? Does Green Lantern make an odd appearance on The Flash (who is going back and forth between the movies and the shows)? Much tighter restrictions (particularly on the shows) if everything's connected.
Then let's talk budget concerns of TV vs Movies, the gap is such a chasm that it also needs to be addressed. Look at Supergirl's effect vs Man of Steel's visual effects. Man of Steel is far superior to Supergirl in that regard, which means if CBS Supergirl ever shows up in Man of Steel her effects will look out of world and be stepped up a notch since it's on the WB budget, and when Henry Cavill Superman shows up in the CBS Supergirl, he will get a massive downgrade because it'll be on CBS's dime. Now imagine The Flash's concerns even taking it further, him going back and forth between shows and movies will provide inconsistent visual quality and there'll be a barrier of entry to viewers in terms of following his stories (and if they solve the barrier of entry, then it becomes easier for the general audience to take preference with The Flash in the movies than it's going to be currently where you know it's 2 different incarnations... Beef or chicken? Here, have both

). And the list of issues only goes further as this universe expands. So what's the only solution? Treat them as separate universes which solves the restrictions on the stories, and creates two (or more) manageable universe versus one behemoth of a universe that runs the risk of being unwieldy, convoluted, and difficult to work around. This also gives us a different variety of comic book movie properties.
And
tl;dr, with these two brands beings presented with different problems to solve, and different opportunities to take advantage of, we avoid DC and Marvel becoming mirror reflections of each other, and instead, they become two opposite sides of the same coin. In the long run as a fan of both, the latter seems like a better case scenario.
EDIT: This is a somewhat more coherent analysis of the philosophies governing Marvel and DC than my original post