I'm a Tolkien fan. The backlash you are referring to from people who actually read the books isn't the racial component, it comes from the fact that they completed changed the timelines of a well-established universe and just made up new events using the names of characters, which is something Tolkien was pretty severely opposed to. Tolkien went out of his way to establish a painstaking timeline for his universe, he took it very seriously as his life's work and was famous for doing things like rejecting the Beatles' attempt, at the height of their fame, to buy the movie rights for the books because he didn't want his work bastardized. The criticism is valid. The criticism about race is a small minority of just racist non-book fans that the showrunners have attempted to generalize as all of their detractors so as to avoid criticism by just calling everyone who doesn't like the show bigots. Pretty common tactic Hollywood uses to deal with critics.
Long story short - Hobbits and wizards didn't exist during the timeline of the show and Galadriel was never a warrior who led armies, but a powerful magic user.
Amazon did the same thing to the Wheel of Time, just arbitrarily changing huge things and mostly for the worse. As someone who read all 15 books of that series, it sucks to have something you invested time in and enjoy trampled on and just made crappy.