Here's my opinion on those reviews. As I'm a fan of the RE series since RE one PS1 (well Saturn in fact) and have played all the main games of the series on day one (RE1/2/3/CV/4/5/6/RER1/RER2), so I have good memories of what was being said on the release of those titles.
RE3 came out at the end of the PS era and few months away from Resident Evil : Code Veronica, everyone only had eyes for this one and RE3 was treated like "meh, it's so old gen". When it was reviewed, people said that it was short, and yes it really felt short. For a single reason : it had only One story to be played. No Chris Story / Jill Story of RE1, no Leon A / Claire B and vice versa of RE2, juste Jill/Carlos story, and it was over.
And that's why for the first time in the series it had a big "bonus mode" called Mercenaries, with many playable characters and plenty of hours to spend if you end up to like it. In RE2 there were the "Tofu bonus" and "Hunk bonus" but Mercenaries was almost like a full game, it was very long and tough.
And they know it, and that's why in RE3 Remake they added the RE Resistance mode, because they knew that the base story of RE3 is quite short. Resistence is the "Mercenaries" of this Remake.
About removing the Befray part of the game (or Bell Tower? I dunno in english as I played it in French), it's because it was criticized because it didn't feel natural at all, it felt like coming out of nowhere and many people disliked this part. It's obvious that they just wanted to reproduce the "RE Mansion" feeling in this RE3. So as I see they removed it and made the hospital part of RE3 longer.
So well yeah as I loved RE3 I'm still pretty hyped for RE3 Remake.