^ Although Marvel did know when they decided to use Quicksilver and Scarlett Witch that this would most likely happen (with different actors playing different versions).
That's the great thing though, we will get the big budget big screen Flash as well in a couple of years. So it's the best of both worlds really. But yeah that's the point. They are completely different mediums, and so it can be really restricted sharing a Universe between them.
For instance AOS gave us the Absorbing Man. Now if a movie has Absorbing Man, it has to ideally be that same guy playing him, with that same back story, and his powers working in the same way. Then if he does appear in the movies done with great special effects, they can't then turn around and put him back on Tv with cheap effects.
Same restriction with them not being able to use Nick Fury on a regular basis.
Then there's the fact that AOS's ratings have really suffered simply because they had to wait until the release of CA:TWS before they could implement their main plot. But by that time they'd already lost too many viewers.
So I honestly think it is probably better to keep them separate.