Give 'em a break
The cognoscenti of every sport think the announcers are terrible. Read web comments by basketball, soccer, football fans all over the place. Most of us know that we'll never be Lebron James or Lionel Messi, but we sure as hell can be Brett Musberger or Paul Sherwin. We know the sport, we're smart, and we know how to talk. We'd be way, way better than Phil and Paul.
Except that's it's a lot harder to talk for 2-4 solid hours than anyone knows. If any of us were to attempt to fill in for Phil or Paul, comments on this forum would crucify us in the first 10 minutes. We'd make so many errors of every kind we'd make Phil and Paul look like geniuses.
I have my own criticisms of them, principally that they won't stop talking, but somewhere they (whoever "they" are) decided that constant commentary is they way you do a bike race. But as I listened to the early commentator on the nbcsports web feed this morning, I realized that their voices are the sound of the TDF to me. When I heard this other voice, although he seemed pretty good, it just wasn't the Tour de France. And then about 9:00 I heard their voices, their cadences, and the race was on.
They're far from perfect, technically or personally, but they are the sound of bicycle racing for me and for a lot of folks, and I won't mind hearing them for a few more years.