I don't disagree. (and we're possibly saying similar things) I think there are 2 issues. XLs - probably need a complete ban as they are so far beyond the pale in terms of size and temperament - and other dogs - including some specific breeds or sizes of dogs that get pulled into the whole 'ban them' debate.
My point was more, if you only ban XLs then the people who want an aggressive attack dog (or a status symbol) will move onto other breeds, as they have before. Probably not staffy types as if they beef them up they would probably end up being typed as pit bulls or XLs anyway, but maybe back to rotties, GSDs and dobermans, or moving on to cane corsos or presa canarios. Then you can keep banning more and more breeds, but the law is never IMO addressing the problem of bad/reckless/downright criminal owners.
As I said I'd like more licensing, more compulsion to train etc. I'd probably also look at adopting some of the laws seen in other countries around leads and muzzles - particularly on public transport, confined spaces etc. There are clearly more dogs, and often in much more populated areas, so I think that we have to look at all the regulations around them. That doesn't mean that we don't also do something specifically about XLs as they are clearly a special case.