I don't think they're actually accomplishing any of those things. I'd argue a shirt is a demonstration IRL of support, which can raise awareness or normalize support for a cause (although not super effectively). Things like this make the "bigots" you are pwning just write this off as the usual DEI bullshit that nobody likes while also turning off anyone without your EXACT strain of identitarian politics, even if they don't actually oppose any specific sentiment in the statement. It is literally counterproductive because it makes you (and your cause) look angry and mean and like the bully.