While you have a right to an opinion, no matter how misguided or asinine, you do not have a right to re-define words to an entirely new meaning.
Definition of a gulag:
a camp in the Gulag system, or any political labor camp.
noun: gulag; plural noun: gulags
The key words there are "labor camp." No jail in which the arrested rioters are held have any kind of forced labor camp.
The opinion of most sane Americans? Anyone currently in jail for their part in the January 6th riots deserves to be there.