From some of the battles ive witnessed, procs can cause wipes. See: brewed Carabosse fail.
And yes, Abyssea in its current state has become a zergfest due to the overkill on buffs but it doesn't mean SE didn't create procs to slow down the DD throw that was all the rage before Abyssea.
It's the same reason I imagine Dynamis and future content will also have procs.