As some of the much, much older Resident Evil fans will know, Usenet was the central point of talk of the franchise in the 1990s leading up to about 2002. Fansites weren't so common back then outside of Angelfire (Unless you count Biohazard Extreme), so to most Internet-using fans all they needed was alt.games.resident-evil. That message board was archived by Google for their Google Groups project, and it looks pretty complete. Below are the things I found while browsing through.
People hated Wesker's Report
The original Wesker's Report was written to coincide with the release Resident Evil CODE:Veronica and was a summary of the series at the time. The writer had taken a number of Capcom developers to bars to get them to reveal in-depth knowledge of the series lore, and hurridly wrote a story which implicated Albert Wesker in much of the series' events at the time. Due in part to problems with the translating and a lot with the poor synching of footage, a lot of fans disliked it. One user said here in August 2001: "Weskers Report is one of the most absurd and retarded things Capcom has done with the RE storyline. It messes up the continuity and outright changes plotpoints from the game."
Hatred for Anderson's film started almost instantly, and a year before the movie game out
After a period of uncertainty when George A. Romero was dropped as Writer and Director, Paul W.S. Anderson was given the new role. The fandom was somewhat supportive of the decision since his Mortal Kombat movie was better received than Street Fighter was. Sometime in 2001 an unknown individual leaked a summary of the film's plot, leading to a huge fan protest of the film, leading to a number of petitions calling for script changes, and even overzealous calls to boycott it.
The arguments were mostly that it "had nothing to do with the games", though the fandom was very confused at the time (especially the guys who admitted that Romero's draft wasn't exactly faithful to the franchise either, but who said "that's different"). For starters they thought that the T-virus and Umbrella wouldn't be in the movie, and that the Zombies were created by an evil supercomputer. This forced Anderson to directly respond to the fans (fan response here) assuring them that there is a supercomputer (thus confirming the leak) and that it isn't responsible for the Zombies. There was still a lot of confusion - it was still believed that S.T.A.R.S. would play a role in the film, and that Alice was a member of the taskforce. This was made worse by Anderson describing his film as a 'prequel' to the games (he was hoping at the time Capcom would accept his script as canon, which didn't happen), which led to people complaining that RE1 implied there had never been an outbreak before.
BIOHAZARD 1.5 was a big thing, and its nick name was "Holy Grail"
Love for 1.5 is as old as 1.5 itself. In the West people were given almost no information of Resident Evil 2 development, and in mid-1997 Capcom USA continued to give out October 1996 material alongside newer materal (people didn't really know of a change in development - just a delay - and figured the new material was of later parts of the game). It's understandable if a few people bought the game and found it had nothing to do with what they were advertised a year earlier. As best they could work out, Shinji Mikami didn't like the game and canned it (not correct, but almost).
It was understood quickly that copies of the late '96 RAMs were sent out to gaming magazines for review purposes, and fans desperately wanted to find a copy of the game. Of course, that created a number of people pretending to own a copy so as to boast. A much worse problem was that of hoax 1.5s going on sale, usually turning out to be the Director's Cut promotional CD or an RE2 demo from January 1998. One "copy" went up for sale on eBay at $1025 sometime in mid-2001, though it was quickly seen as a fake by most fans due to the seller's short selling history (here), though this didn't stop one guy from buying it (here). Nothing said on if he was conned or not.
Another unfortunate side-effect of the 1.5 buzz was that the more zealous 1.5 fans become no different from the True Fans(TM) of today and demanded that fan sites put up banners demanding the release of 1.5 and attacking Capcom for canning that version of the game (which, let's make clear, was virtually unknown in the West due to aforementioned lousy advertising - so they were complaining that something they never saw was better than RE2). Heck, a lot of them couldn't tell 1.5 from Preview's alternate ending with Ada in the S.T.A.R.S. room, anyway.
Hatred for new games began with RE3
It's common now for Truthies to circle-jerk over the latest Resident Evil game before footage is even released - we can see this with RE7 now. In some ways it was the same in 2000. A lot of bitterness at the time was with CODE:Veronica, which was seen as being far less 'scary' than the earlier games. However, dislike of Resident Evil 3: Nemesis was also appearing, with people seeing it as an unworthy entry in the series - at least as a numbered title - and absolutely hated the ending, which depicted a large bomb destroying the city. Around alt.games-resident-evil there was the one question: "Has RE run its course?" That RE3 didn't outsell RE2 was seen as conclusive proof to some. Even in 2001 people were lamenting that Resident Evil 2 was the last great game and the zenith of the franchise's popularity ahead of a long decline afterwards. In retrospect we can see why the games changed with Resident Evil 4.