Work in a bike shop as a mechanic for just 6 months. That will give you a better idea of what is going on in the cycling world.
MTB has shrunk while general cycling has ballooned. Repairs and servicing are getting expensive. Forks and bushings are more complicated creating a more stressful relationship between the owner, bike itself and the retailer. Full suspension is a joke. 99% of the time you dont actually need it and can ride just as well without it but the magazines say otherwise. The whole MTB business would fail if we all just got on with cycling rather than hung up on what fashion tells us we need.
While I agree with most of these, I believe that only a person who is stubborn enough not to try new stuff would say that ALL new bikes are crap. If so, why limit yourself to the nineties when you can ride an awesome klunker with a drum brake in rear and that's it? Who needs better stuff? In the end, it's still a bicycle...
I am not a mechanic, though I am eating MTB day in day out. You don't need a mechanic to understand certain things or to have an opinion that you can sustain. The industry needs the hype to survive it's own growth and the media is biased and there once in a while there is am oasis of honesty, but that doesn't mean bikes are not good or decent. Try telling me that last year's 150 mm Enduro is actually worse than some 1990 Stumpy with rigid fork, 135 mm stem and M730 cantis and I'll know that is bullsh_t, because I've ridden them both.
This is all retro-bullsh_t and most arguments are about looks and style, let's be honest. It's okay to cherish the old, I do too, but why build gratuitous shrines for anything old and falsely claim it's better when it's obvious it's not? Let's keep a balance! There good stuff on both sides; why not have the best of both worlds? While saying that I have a blast regardless if I'm riding my 2011 Commencal V.3. my 2002 Cannondale Jekyll or my 1993 Karakoram; they're all good bikes. Actually, if we stick our heads out of our arses we'll notice that ANY bike is good, as a matter of fact, as long as it works and you can ride it.
Ride and stay happy!
1990 GT Karakoram 20" Purple Haze (urban project); 1993 GT Karakoram 20" Ferrari Red (classy beater); 1993 GT Karakoram 14.5" Black Light (almost original); 1994 Breezer Jet Stream 18" (unlikely story); 1995 Winora full suspension (a fine riding mistery); 1997 Kona A'Ha (anniversary edition); 1997 GT Arrowhead 18" (poisoned gift); 1998 Stevens 6.1.2 (true warrior); 1998 GT Moto cruiser (just google it!); 1999 Santa Cruz Chameleon (the heartbreaker revived); 1999 GT Lobo 1000 (retired with works Super T); 2000 GT Lobo (turns original); 2001 Klein Attitude Comp 19" (ultralight project); 2001 Cannondale Jekyll 1000 SL (better that a lot of "fresh" bikes); 2003 Intense Tazer (close to factory team spec); 2003 Intense M1 (old dream on hold); 2007 Crupi Pro XXL (pumptrack teacher)