I think it's a little more complicated than that, but that's the gist of it.
Dave was unhappy about the direction of the music Eddie was writing. He was unhappy about the world's greatest guitar hero playing around with keyboards. He was unhappy about the greatest party rock band playing sappy pop love songs. So it wasn't entirely Dave wanting to do a solo thing. There was a genuine artistic difference. It wasn't Dave's fault that he was unable to sing (or didn't like) the songs Eddie was writing. And it wasn't Eddie's fault that he wanted to expand his artistic vision. Dave (and Mike) limited what the band could do.
Ed was not pissed about Sammy's solo album that I've ever heard. Sammy claimed that Eddie told him not to hold back and save any songs for VH--to put his best work into the solo thing. And they even let Sammy do an acoustic solo song off this album during VH shows in the early 90s. (It was beautiful and a nice break during the show).
I'm not sure why they stopped working together in the 90s. Their last album together was their best, IMO. I didn't even buy it until last year, because I was increasingly bored with their music. I didn't even give it a chance. I heard "Humans Being," and figured it was more of the same. But Balance is a darker, more introspective album than all the other Hagar stuff. Eddie wanted to present less of a "party" persona, and wanted to focus on the music. He hated the lyrics to "Amsterdam," for instance.
I still haven't listened to VH3, the studio album. I've heard that it's the most different VH album ever made--that it's pretty much a EVH solo album. I've heard it described as experimental and musically challenging. Maybe this is why it didn't have a lot of popularity. Or maybe fans couldn't accept yet another frontman. Live, Cherone was a very good mix of SH's range with DLR's raw edge. Cherone sang the classic VH stuff better than Sammy. He was able to sing both eras fine, straddling that fence. Check out the Youtube footage of that tour. Eddie rocked, and Cherone was decent.
www.youtube.com/watch?v=oHcvLtfW6FI
Check out this one with Mike singing lead!
www.youtube.com/watch?v=u69ICykgnYo&mod ... ed&search=
Eddie was sloshed during the 2004 tour, and apparently played horribly. THAT was a money grab. They didn't look happy together at all, and the new songs sucked.
I don't think this latest outing is a money grab. Sure, they want to make money. But going into rehab in order to give the audience the best possible show isn't something you do for a money grab. Bringing your son into the band--practicing with him for years--isn't something you do for a money grab.