Small dogs are more aggressive, big dogs can do more damage. Ultimately, it’s a matter of training - how are they raised? - and a matter of the owner maintaining control. I really don’t believe in the whole “some breeds are inherently evil” thing.
I don't think anyone really claims that; or at least very few people claim that. It's about averages in behaviour, combined with the greater damage you mentioned. I think almost everyone agrees that on average there are differences in personality between dog breeds. These dogs have been responsible for more than half of deaths in recent years, and I don't think half the dogs in the UK are Bully XLs.
In the end basically nothing at all is lost by banning a few breeds beyond upsetting a few people who want a dog in a very peculiar shape and accept no other shapes, to which I say: "if you're such a dog lover then why do you care so greatly about the exact shape of your dog?"