Nobody is dying because of a paragraph in a D&D book, it previously wasn't exclusionary. That there is more representation now is a good thing, but people weren't excluded just because they weren't represented.
That is simply not how human social processing works.
It has become more explicit recently but all sorts of people have always been welcome before, nothing in the industry has ever explicitly barred anyone from playing.
They've never been explicitly barred from playing, but they've absolutely been explicitly barred from being characters in games, and that has been quite reasonably taken as a hint.
Individuals in the hobby might exclude people from their groups based on their prejudices (not that I have ever seen any evidence of this), but I doubt a paragraph in D&D manual is going to make them more welcoming if they weren't before.
If you can sincerely say that you've never seen any evidence of people being excluded from groups based on prejudices, I put it to you that perhaps you are too far from the question to have any relevant experience, and should defer to the people who have had these experiences and seen these things happen, as they have some conceivable way of knowing what they're talking about.