They're right about it not killing as many birds/bats as other things, but the problem is that THESE are in ADDITION to the other things, which aren't going away. And wind power is still rather nascent.
Also, the birds that get killed aren't often pigeons or other city birds, but more likely migrants or even worse, low-population raptors. Wonder how many bald eagles these mammoths have killed.
Funny how PETA doesn't rail about the birds and bats cut in half by turbines.
A better alternative is stratospheric kites. But those are still in development.