Very few people who were frum beforehand went OTD because of the lure of the Zionist movement alone. Had the Zionist not existed they would have found some other OTD movement to join.
For all their faults and personal opposition to religion, the Zionists did not run around preaching abandon Torah and join us. There are plenty of movements that did that you barely hear about. Because most of the anti-Zionists are only interested in fighting with those who they can accuse of being Zionists. They don’t seem to have any interest n fighting other groups who acted and continue to act worse. They have no problem giving kovod to members of the the latter groups when it suits their purposes. They certainly never initiate conflict with them.