The official forum could be fucking brutal sometimes. When Reroute first leaked, the place turned into a fire zone. People were PISSED. In fact, most places I frequented were. I used to be part of a few IRC channels and DC++ hubs and people couldn't believe it. It had started when Clayman came out but was nowhere near as bad as a few years later. From my memory (which was 20 years ago obviously), In Flames was loved by almost everyone in the "underground metal scene." As people tend to do, they took it personally when Reroute came out. It was an absolute disaster and there were very, very few kind words coming from anyone who hadn't just recently discovered the band.
I remember seeing Nevermore and Opeth in '01 and a group of maybe 6-7 of us were standing around between bands, talking, and the subject of In Flames came up. This was before RTR obviously and even then people were like "ehhhh, Clayman is the beginning of the end for these guys." I would've been 16-17 at this time and I was confused. I liked Clayman a lot and didn't really see it as a decline in quality. Different, yes. Man, I was blind. Fast forward a year and I was massively disappointed. I was on IRC and somebody shared the album with me. It was like Christmas morning for a little kid -- just beyond excited. Then I started listening to it. It was like somebody knocked my Christmas tree over and just pissed all over it. Even now, I really don't like that album. And I think a big part of it is because of how gutted I was back then.
For the band, it must have been seriously disheartening to read through those forums. There was some mean shit said on there. Looking back, I am not surprised at all that they took it down. New fans coming in and just getting ripped to shreds. Not a good look for you when your fans are coming in to talk about the new album and just getting fucking roasted.