Minorities and women are sure welcome, but ideologues from the outside marched in and started telling everyone on the outside that they don't seem to be welcome enough
Fans are part of society. They have always been rather more welcoming of minorities and women than society (if tri-gendered species can be competent, then stating that women cannot be competent is odd), but as society has become more accepting of others so has fandom.
Now some puppies (who are part of fandom, but not the whole) have started saying that fandom is TOO accepting. Which confused many people. And the puppies nominated works based on the political views of the authors rather than on the qualities of the work. So when you don't select works based on quality, those works don't tend to win awards given to the best-quality works. Seems reasonable.
Note that nobody came from outside. And the people who tried to "change" fandom were the puppies, not the rest of fandom. Turns out that a majority of fans are happy with diversity; if you're not, well, that's fine, but please stop blaming "ideologues from the outside".