From my perspective, it was always drunk Jerseyeans who misbehaved at the Parade and in Penn Station. But I’m sure you’re right about Bronx residents. The real problem today is the Santa freaks during the Christmas season, not the parade.
That being said, "ethnic pride" is for those who don't have anything in their own lives to be proud of. Old joke about the St. Pat's Parade is that it is where the Jews of Fifth Avenue get to watch their employees on parade. :)