The push to ban bullfighting has to come from the Spanish people themselves, outsiders cannot do it. It may have been a leftover from another time, but in old days, people used to have plenty of barbaric, inhumane practices, nobody thought anything of it.
But as we progress, it is time to shed some of the more atrocious, primitive practices. Britain banned fox hunting. That was a big step indeed for Britain, Britain banning fox hunting was similar to Canada banning hockey, it was very popular among some factions in Britain.
However, Britain rightly recognized it as a barbaric practice and got rid of it. Hopefully Spain will follow suit, region by region.