From your use of the word "leftists", I suspect you and I wouldn't agree on much; however, on this point I agree with you. Someone above mentioned the "paradox of tolerance" and I think your observation fits perfectly with that. I feel strongly about many of the same things that BLM and MeToo does (just to give some concrete examples) but I don't think believing in those things necessitates erasure of people who think differently. Unfortunately you find a lot of the "erasure" sentiment out there and usually they are the loudest voices.