Id compare this to the relationship between JR and Austin. Hearing JR say "Stone Cold Stunner, One More Time!", made him the voice of Steve Austin. While JR was doing this as a face commentator for Austin, I think it's perfectly fine the way Cole is doing so with Miz. Even his interference in the match tonight made sense, as Cole has been Miz' biggest fan for a long time.
Just one point I'd like to make here; you're relying on the assumption Ross' and Steve's relationship, both on screen and off, is similar to Cole and Miz'. Not true, sir. We may not have known it then, but Jim was instrumental in getting Austin his job in the WWE. On and off screen, these two were best friends, the likes of which forms a chemistry you really couldn't have any other way. Ross was so passionate, because of all the personal interest he had in Steve. There's no way to duplicate it, frankly.
Anyway, Cole is good for his time, really is. He is an actual broadcaster, so yes, he's doing his job as he's supposed to. He's coming off having to replace Jim Ross, and because people have become so accustomed to Ross, there's really nothing Cole's going to do to be able to help his stock. I would like for any fan to tell me what exactly they have against Cole. That he doesn't have any ring experience? Fact: Neither does JR's fat ass, yet he comes off as more "legitimate". Sure, sure, tutored under Bill Watts, blah blah. Like that really means fuck all to most of you, but humor me; let's just say Ross' background is more "legitimate", for a lack of better word. So what? What really does that help you with? To help sell the programs? Do you buy tickets just for JR, Cole, the King, etc? No, no you don't. You buy it for the actual program, and the commentator is there just to help sell the theater of the match. Cole does that perfectly fine, and is the most fit to hold down the voice of the WWE. He sells the impact of moves, he sells the meaning behind the match, he even sells the implications of the results, I'd say, better than Ross did at times.
Cole is perfectly fine for what he is. Anyone telling you otherwise is living in a delusional world where Gordon Solie still is the standard bearer in commentary, and what all commentators should strive to be. We've evolved too much; Cole is just another evolution