Especially when compared to the first two movies with Cameron Diaz, Drew Barrymore, and Lucy Liu that arguably, made them such a joke: No guns, dated slapstick comedy, and they were equally dumb and came off like bimbos.

Did a lot of the so-called "hate" of the 2019 reboot at the time, come from the simple fact that was starring Kristen Stewart and it being deemed and marketed as a "feminist" movie?

If the reboot starred three popular and likeable American actresses of the 2020s, it would have been better received? The Charlie's Angels franchise you can say, should be focused on grown women, not ingenues.

Also, would the film gotten more support had they included Jaclyn Smith in the actual film and not at the end and had they got the first movie trio to appear in some fashion?

Nah, it really was that bad. The first 2 movie worked precisely because they had made a joke out of it and had fun with it. Charlie's Angels made as serious movie would never work.