The true greats of the play-by-play business aren't homers. They give the entire scope of what's happening to enlighten fans and to make them smarter for listening to them.
Fans of one team don't generally know a lot about the opponents. It's the announcer's job to enlighten folks listening/watching about some the players to watch out for, some of the intricacies about the opposition, etc.
It's funny, Mike Lange has been called one of the biggest homers in pro sports over the years, but those people only know him for his goal calls. If you LISTEN to Lange, he will go on and on about the opponents all the time, and he'll give you a lot of info that a casual fan may not know. Listen to Vin Scully in baseball. He knows everything about every player, for either team. Dick Irvin used to be like that, too (former Habs radio PbP man). Doc Emrick, as annoying as his voice can be, is also like that. When he was the Devils' broadcaster, he spoke highly of their opponents all the time.
I don't know. Maybe it's just me but I thoroughly enjoy listening to classy broadcasts...and classy broadcasters.
Mike Lange is just that. Dumb & Dumber on TV certainly are not.