/shrug
Thats sort of the entire point of Skyrim, dragons.
Be similar to playing football with a baseball.
People would be like :

I don't seem to come across that many of them, not to the point of annoyance mind you, but I suppose expanding on P-Nax's role in the narrative to let the dragons retreat to thier respective corners of Nirn would be nice.
The majority of dragons have been gone/dormant for a long...long....
long time. I would think they relish the opportunity for a little payback on the mortal races sending them away.
Consider how many people there are in Nirn, 91 dragons doesn't seem terribly unrealistic. 9,991 dragons wouldn't be outside of the realm of possibility either... especially considering Skyrim is the hotbed of thier reanimation.
Who knows how long Alduin was raising dragons before the raid on Helgen?