A word's only job is to communicate, and Jewish tradition has always been willing to retire, rename, or route around a word once it stops doing that job, without abandoning what the word was created to protect. “Zionism” was coined to communicate one specific idea: the Jewish people's right to self-determination in their historic homeland. For a large share of the audience Jews most need to reach today, it no longer transmits that. That's not a PR problem that is the word failing at its one job.