By separating his playing out by genre among many different groups, he's able to continually be out in the marketplace, building his "brand" in each of those different genres. It may not make him as "interesting," but it does put him across a wide array of genres, and increase his marketability. Obviously, I don't know MP at all, but reading the tea leaves, it seems like marketing and business have something to do with how he has diversified what he does in his post-DT career.
It makes total sense that finances and the business side of things would be a motivator post-DT. But I think that is likely only part of the picture. Another is that he is just driven to be involved in lots of different things. He likes lots of different types of music and likes to be involved playing those different types of music. It was the same when he was in DT. At any given moment, regardless of what DT was doing, when there was down time, he would be looking to fill it working on Neal Morse solo material, working on Transatlantic, doing various tribute projects (The Who, The Beatles, Led Zep, Rush), or other collaborations/projects. Heck, he even recorded a backing vocal track for a Neal Morse project backstage at a festival when he was still with DT. He just can't help himself.
I think it would take him landing a REALLY big, well-paying gig where he wasn't in control to really limit him doing lots of other diverse side projects. For example, if A7X had offered him a permanent spot and put their foot down about him doing other things when they weren't touring, or something else big like that. And even then, I think he would still do some limited side projects just because he just
has to scratch that itch.
EDIT: At the end of the day, while it is likely that money plays some role, it's hard to say how much of it is that and how much of it is just Mike being Mike and wanting to be involved in as many diverse things as humanly possible. I'm not so sure he can even answer that. And like Cram said, there's nothing
wrong with that either way. It just is what it is. And while it may leave some fans frustrated, at the end of the day, it
does ensure that there is a little something out there for everybody. You have people that would never buy a Sons of Apollo album who love Flying Colors, or people who would never buy a Neal Morse album loving The Winery Dogs, etc.