Also, think of the sheer numbers of our guitar heroes that play traditionally designed guitars... On Strats you have such diversity, from Buddy Holly to Yngwie. On the Les Paul you have The Man, Les Paul himself, to Joe Perry, to Zakk Wylde. These players endorse their respective guitars, and endorsements sell.
A number of different designs came out in the 80's from Ibanez, Jackson/Charvel, Steinberger, ESP, Kramer and others, as a reflection of the more "flashy" styles of music that era. As the 90's kicked into high gear, dayglo holographic paint jobs went out of fashion, and guitarists turned to a more traditional or "vintage" look to their instruments. It became kinda hard to get into a Pearl Jam tribute band playing a dayglo polkadot reverse headstock Floyd Rose shredderiffic masterblaster.
However, what goes around comes around... With the resurgence in popularity of '80s music, and NuMetal (please pronounce that with the umlauts), solos are back in fashion in rock music, and more and more guitars are "built for speed." I'll bet we'll start seeing more "flash" and some different designs again, and in greater numbers.
Guitars:
Fender 2006 MIM Fender Stratocaster HSS in 3TS
Ibanez RG 570 with a bridge Invader
ESP M II Deluxe with a Tune-o-Matic bridge
Eleanor, the magical, mystical Road Worn wonder Tele
Blackstar HT Club 40