Really? I asked quite a few friends and family when this debate first arose and none of them made that association. Maybe in America but not suburban Britain.
As for stupid and irrelevant nicknames, where would you draw the line? Witches ( occult)? Pirates (criminals)?
Worst case scenario is we'd end up with all nicknames having to be selected from a PC-approved list of cuddly happy-clappy ones.
Speedway is an extreme sport and nicknames are a good way of reflecting that.