What is wrong with signalling virtue?

The emphasis is on vapid. Do you really not understand why people respond negatively to someone interjecting with some hardly-relevant comment just to make themselves look good?

you said that volume =/= value. To me it seems you don’t like when people try to be social and expressive, at least around certain topics.

That was specifically about you saying that you had "given a lot". Just because it's "a lot" doesn't mean it's valuable.

You haven’t elaborated on what racial injustice looks like to you, you’re just gate keeping other people’s definitions.

Actually I haven't done either. Because it's not particularly relevant to my point.

Those other definitions of racial injustice are vapid

I didn't say the definition was vapid. I said the act was vapid. Again, a wall of text about something I didn't say or do.

Please elaborate on who the victims are of that comment you originally responded to.

Again: at best, the people who have to rifle through those inane comments, and at worst, the people who's actual problems are diminished because the signal-to-noise ratio is out of whack.