I will always call out discrimination in any context even by well meaning people. I do hope that arguing against racism and sexism is acceptable on this forum.
Arguing is generally acceptable on this site when there is an actual, logical argument. You didn't argue anything, just expressed your opinion that it is bad without explaining yourself.
Since this is continuing exactly what I asked you to stop, I've banned this account until we get some indication that you want to use the site as intended.