Opponents of the state's name thought the word "plantation" was a reminder of slavery and were offended by it. These opponents are clearly not historically savvy - plantation simply meant "a newly established colony." Plus, in all of the state's early slavery debates it was Rhode Island (not the anti-slavery and anti-slave trade Providence Plantations) which favored the position of slave traders.
History won (with 99% of precincts reporting), 78%-22%. We still have a State of Rhode Island and Providence Plantations.