That is true.
But on the other hand, the Ultimate universe has outlived it's purpose and creatively is in a bit of limbo. Sure, when it started, it got a lot of interest, sold VERY well (these books were Top 5-10 sellers in their heyday), helped recruit "talent" to Marvel and helped infuse "ideas" into the core line, for better or worse. It also provided some more updated versions of stories and characters for mass media interpretations, giving them another option.
But now? Aside for USM, and somehow the Ultimates, none of the books sell within the Top 25-30 anymore; even USM has bled a slew of readers since Bagley left. They're not bringing in A-list talent to do the books, and there is no buzz. Any innovative idea Ultimate had has been strip-mined for 616, and aside for Bendis on USM, just attract B-list talent (Loeb is officially B-List now). Retrenching into lessor titles makes common sense, even if the books were still selling alright (UFF was still a Top 60 book). The Ultimate line is just running it's course like a lot of alternate reality lines. Granted, it has been more successful than the NEW UNIVERSE or 2099 were in the 80's and 90's, respectively.
I bailed on USM after the Clone Sage garbage and every time I get curious enough to flip through a random issue on the shelf, I am reminded why. Kirkman ran ULTIMATE X-MEN into the ground HARD after Vaughan had injected life into it. And Ult. FF just became middling to me. Smelling Loeb & Joe Mad's ULTIMATES 3 was going to be a stinker, I jumped ship more than half a year ago, and haven't regretted it.