The only one who has the guts to admit it.

Actually I understand the hate.
I'm thinking some small part of it might be that these novels are equivalent to an adult rated movie while most Star Trek books would be PG at worse, You'd be happy for your young teens to read them.
Star Trek isn't a franchise that has realistic, gritty portrayals of the extremely negative aspects of life like Walking Dead or Silence of the Lambs so it would be strange to see stuff like murder, rape, domination in Star Trek novels.
Still the M&C novels to me are a bit different and I suppose the early authors had a certain freedom so you weren't sure what would happen. Still I didn't like say "Spock:Messiah" because of its sexism and character portrayals and its adult concepts.