Why is this a dick move? It only applies to further work done on the project. By licensing your work under a BSD/MIT/etc. style license you explicitly gave any

Why is this a dick move? It only applies to further work done on the project. By licensing your work under a BSD/MIT/etc. style license you explicitly gave anyone permission to use the work in nearly any way they wanted, including as part of a Apache, GPL3, or even completely proprietary closed-source project. If everyone else on a project decides to use a different license than you picked for their future hard work, that's their choice, not yours.