WWE goes through commentators as frequently as Vince McMahon changes his mind regarding creative plans, and very rarely does the company settle on a single announce team for one of their shows for a substantial amount of time.
Commentators can be called up from NXT and then demoted back down to developmental in an instant, as well as be switched from SmackDown Live to Raw and vice versa. Obviously, some announcers are better than others, but at the end of the day, it's merely a matter of how high officials (and specifically Vince McMahon) are on them.
There have been some pretty deplorable commentators over the years in WWE that were around for a lot longer than they should have been because they had support from the boss. In other cases, talented talkers have been close to becoming the next voice of WWE before one mistake cost them their spot behind the booth.
Either way, McMahon ultimately soured on them all, regardless of whether they deserved to be or not. It's no secret McMahon plays favorites and has pet projects of his own, even on commentary, and the following eight announcers are prime examples of individuals who were at one time favored by the boss -before Vince became disenchanted with them.