It has been my (completely anecdotal, I will grant you) experience that fans' opinion of the play-by-play man tends to be directly proportional to that given fan's opinion of the team the play-by-play man represents. Someone who likes, say, the Kings, will overlook, and even laud, behavior from their broadcast team that makes them want to throw things at their television when they hear broadcasters from rival teams act the exact same way.
As to the question of Napear, he is awful because he is overly opinionated (that's the color man's job, not the play-by-play man), and obnoxious. He is also disingenuous, trends towards hypocrisy, and is too much a company shill for my tastes. He praises who he's told, and he slams who he's told (e.g., his gag order about the coach), and only who he's told, and I can do without his particular brand of brow beating/proselytizing.
I generally consider "passion" to be overrated on the part of the play-by-play man and, to the extent that I do want to see it, I prefer it to be of the reasonably neutral Kevin Harlan/Mike Bennett/Matt Devlin variety, as opposed to Napear's "company stooge" variety.
That elaborate enough for you?