I don’t think this is an unpopular opinion in the slightest among leftists. The general underlying principles remains the same, the only thing that changes is people’s depth of understanding of the subject matter.
Similarly, I don’t think there are many people that defend the undeniably bad things done by ML states, just like there aren’t many liberals who’d defend American Slavery or the Trail of Tears.
People who I see called tankie most often are MLs who defend the non-shitty things done by the USSR, such as guaranteed housing, free Healthcare, and free education, and assume they also are therefore defending things like the Katyn Massacre or Moscow Trials.
I’m not an ML, but that’s why I asked the question, more aimed at OP than anyone else.