Ironically, I think it's actually the other way around. OG RE3 gets a bad rep because of a loud minority whom considers the RE2/CVX storyline to be the true RE3 even though that's not the case. And RE3 is actually not a short game if you compare it to a single scenario from RE2, they match up pretty well when you look at various longplays and speedruns for comparison.RE3 has always been considered a weaker title by the general RE public and usually a lot of people's "least fav" out of the classics along with CV, which is honestly why all the complaints about sticking to the original more closely absolutely floored me! So many people complain about the game from the length to it being uninspired sitting between the complexities of RE2 and CV. They changed some things for the remake and it still wasn't good enough. You really can't make everyone happy.
I wouldn't presume that everyone hated RE3R just from the loud protestors. I thoroughly enjoyed my time with it and think the remake gave it more replayability.
A remake of RE3 was in extremely high demand from people following the release of RE2R, I thoroughly remember every comment section on YouTube, Facebook, etc being flooded with this. For a game "being considered a weaker title by the general RE public" in your mind, I don't feel that kind of demand would've happened. If you look at comments sections now they're not exactly filled to the brink with people demanding a remake of CVX (which you put on the same level of "least fav" along with RE3) even though it does happen.
I don't think anyone with a reasonable mind has suggested that "everyone hated RE3R". However, it is fair to suggest that it has received a pretty polarized response, especially considering there are so many people who really like the original.
When you say "they changed some things for the remake", well that's a huge understatement. I understand if you don't like RE3 but they didn't change "some things for the remake", the remake is almost a complete overhaul from the original. I've just replayed OG RE1, RE2, RE3 back-to-back with REmake, RE2R and RE3R and it's astonishing how closely the remakes of 1 and 2 mirrors the originals while the remake of 3 is so far off. It's a completey different game that keeps a few basic plot points from the original.
That's not saying RE3R is a bad game. It's just a terrible, terrible remake.