To the casual observer it seems the factories were putting more effort into who could come up with the most hideous fluoro graphics package than innovations on the bikes...
The bad acid trip graphics were a big part of what made the 90s awesome.
And the best/worst of the worst were the 92 RMs:
That said, it was an era of technical progress, just like every other era. USD forks, USD forks that didn't suck, back to RWU forks, better power delivery, multi-stage power valves, 19" rear wheels, perimeter frames, more-modern ergos, more modern handling, two-way adjustable forks, big footpegs, 54x54.x 125s becoming universal, dual-chamber forks, blah blah.
But of course, that all gets forgotten when you have graphics/colour schemes as awesome as this: