Crimea was already annexed by the Russian Empire and then the Soviets about 200 years and got transferred to Ukrainian SSR in 1954. Administrative, not exactly annexation.
If Crimea didn’t have the option of leaving Ukraine when the Soviets collapsed, then your point would have some justification.
But they did. And they chose narrowly to remain as part of Ukraine rather than becoming independent and probably end up joining Russia again.
By your logic then you should be supporting their recent vote to join Russia and just shut up about it.