The arguments against are not based on any logical or rational footingHow convenient it must be to believe oneself to be in exclusive possession of logic and reason. This is not the way to charitably interpret an argument.
The biggest reason these features should never have been added in the first place: the more opportunities everyone has to notice and be reminded of everyone's differences, the longer those differences will remain divisive.
The saying used to be, "On the Internet nobody knows you are a dog." We were all brought together by the common language of text. I became friends with people of many nations, colors, and sexual backgrounds. Now, every single interaction has to be labeled with your "identity," as if a single color code point could remotely capture that, and it drives us all apart.
This is amplifying exclusivity in the name of inclusivity.