It wasnt an outcompete thing. They spread by taking over and feasting on other hives and killing everything in it… Hence the “murder” in the name. They were poised to take over local pollinators because North American bees never evolved to combat against this tactic like Asian bees had.

I do agree though that the name made them sound a lot scarier than they actually were to humans but left unchecked it wouldve been devastating.