I agree that ISIS should be destroyed because it wages attacks against the US and Western countries, just as Al Quaeda and its Taliban enablers needed to be destroyed after 9/11. What I don't agree with is using ISIS and 9/11 as an excuse to wage war and occupy nations that have nothing to do with either, or as an excuse for staying for decades after the military operations are complete to nation-build.
I don't withdrawing from Syria if ISIS no longer deemed a threat and the Kurds are armed can handle ISIS and defend themselves.