Do you ban firearms too? That kind of thinking is a lot like the libs who want to ban ALL guns because they can't possibly consider the fact that there are responsible gun owners. You obviously don't understand the concept of personal responsilbility.
I understand where he's coming from, I've never been a landlord, but I have seen some VERY irresponsible tenants. By and large, people don't appreciate what they don't own.
We did not have dogs when we lived in an apartment - we had cats. Now we own (in a non-restrictive covenant suburb!) and can jolly well do what we like with our own place.
But I think that a security deposit, to be employed towards repair/cleanup if the pets misbehave, is a reasonable compromise. Set the deposit high enough to pay for the cost of cleanup in most circumstances (I don't think six months rent covered the replacement of the wood floor and joists in the second BR in our old apartment, but that was an unusual situation.)