Actually, blink is very much the reason why AVA as a band died.
At the time, they were going strong, touring and functioning like a normal band. But at the time Tom rejoined blink, and they started touring, AVA got less and less time on the road, which led to the point were Atom left. Tom has even talked about this in interviews, telling that Atom is a roadster, he loves being on the road, and when AVA stopped touring, he left to find another gig. Even Atom has said this in interviews with Against Me!, saying that he loves to tour, and must be out on the road!
At that point, AVA got less and less time on the road, leading to Matt quitting to get a "real" job, don't forget, these musicians get their money while touring nowadays! And that's probably what happened with David to!
Its the exact thing I was hoping NOT to happen when the news came out about the reunion.. And it sucks that I could foresee it! But I don't think it would've happened if Tom didn't reunite with blink as there were no signs on it.