So basically Mike leaving AMob is because they weren't going to make enough money for him.
That's pretty much what most of us assumed all along. At least he came out now and actually said it.
To be fair to Mike, he said as much in his interview for the Classic Metal Show last year :
https://www.spreaker.com/user/cmsrocks/interview_with_mike_portnoy.
Honestly, I'm not that surprised. To say A. Mob got a mixed reception from the metal community would be a gross understatement. To have a band with two progressive metal giants turn out to be so.... mundane, was surely a disappointment to a great many metal-heads. It was no surprise for me to hear that A.Mob did not turn much of a profit.
As for Russ, considering that Symphony X only does two albums per decade, I don't know how much of a revenue stream that provides for him. I've long postulated that SX's lack of activity is why he does so many projects on the side, from Atomic Soul to Allen/Lande to Ayreon to Star One to WhateverArjenAnthonyLucassesndecidestocallhislatestproject. I would not be surprised at all if Russ becomes one of the more regular singers for TSO, now that he got his foot in that door last year. That was probably a big payday for him, and it exposed him to literally millions of people who have probably never heard of him before. I know if I were him, I would be wanting to make TSO as much of a full-time gig as possible, and not just because I'm a huge Savatage fan....