I just read something where the singer from Slipknot said that James Hetfield told him that he feels like the most hated guy in America sometimes because of how crappy Metallica's fans are. So yeah, I do think it gets to them now and then. Meanwhile, what's he supposed to do? Rewrite the first album 100 times? Take polls? Nah, I think the best attitude is "---- our -----y fans." That's what I would do.
Every band faces difficulties with staying relevant, it's exactly HOW Metallica has handled those difficulties that irks some fans.
The first issue is what happened to them in the 90s. Almost all of the major trash bands that were putting out insanely good albums in the late 80 through about 1992 were blind sided by grunge and saw their markets almost immediately start to evaporate. Many bands, Metallica included, shifted gears and released albums that were intended to keep them relevant but instead alienated their fan base. Youthanasia; terrible. Sound of White Noise; not even recognizable as Anthrax. Exodus' Force of Habit was so bad the band broke up for 12 years. The Black Album, Load, Reload; attempts at alternative radio rock that was never going to get on the radio and never going to be appreciated by their fans. They all tried too hard and were punished for it.
Second, Metallica made a legit effort to get back to speed/trash with St. Anger, but the recording was really one of the crappiest things ever purposefully put on tape; it staggers the mind and offends the ears. They had Bob Rock sort-of play bass and Lars sounds like he's playing trash cans. His two kick drums aren't even mixed the same. They either weren't paying attention or purposely said F it.
Third, Death Magnetic brought in a legit bass player that is almost completely inaudible on another recording that so so poorly mixed that is sounds like Lars' snare is right next to your head. The entire thing is really the gold standard for how the Loudness War can make an album completely unlistenable. Not that there is a single memorable song or riff on the while CD anyway.
Also somewhere about the time the self titled CD came out James must of had a stroke or something because he forgot how to write lyrics. Really examine the imagery and ideas expressed on Master of Puppets and Justice; they are far more engaging and adult than the pseudo biker bar stuff on their last two CDs. Its like going from To Kill A Mocking Bird to Twilight.
Now, before I'm written off as an angry "they were better then" guy, I'd like to point out that I've given them chances. I own St. Anger and DM, I try to listen to them every once it a while, but they just aren't good by many measures. I don't care about the "sell out" thing. I love it when a band I like makes money. I'm super pumped that Opeth is as huge as they are now because when I started listening to them in the late 90s they couldn't even get proper US distribution. I totally dislike their last 2 CDs, but I don't hate them for being popular. I've listened to Slipknot since their self titled CD and have never knocked them for being popular. I see the hate that's thrown at them, which is really generated by the fact that they are huge. The bigger you are the more people like to take shots at you; I get it. But a lot of the misgivings about Metallica isn't about them being big. They were huge when And Justice for All came out, I loved that they performed One at an awards show and was super pissed about the infamous Jethro Tull incident. It's because they shifted gears in a way that left people scratching their heads.
They could be so much more as band. Judas Priest and Iron Maiden have been around longer survived more drastic changes than Metallica and don't have the same backlash. Metalheads are really into highly technical playing right now, I think Metallica has the ability to put out some brain warping stuff, especially if they let Rob off the leash.