quoth self:
Processor socket: because physical sockets are expensive and for most current designs make thermal management a pain the butt.
If you were thinking of package and pinouts: because not every chip design lends itself well to the same package and pinout. While some of it could be harmonized, there's really little incentive to do so. Most new chip designs are going to require new board designs anyway, be that for power management, decoupling, thermal management, etc. Going with some 'agreed-upon' package/pinout would be limiting the possibilities.
( Note that there have been exceptions, e.g. the BitFury Rev1/Rev2. Rev2 was pretty much a drop-in replacement, and could be applied to existing designs, and even replace Rev1 chips for those willing to desolder the old chips. Not that much 'waste', though I think applying to new boards + components would be more cost-effective; can't easily resell desoldered older chips, but reselling an old functional miner isn't terrible. )
Those are some good points but couldn't the same also be said for CPUs?
Back in the late 2000's, Celerons, Pentium 4s, Pentium Ds, Xeons, and Core 2 Duos all have completely different thermal profiles, power consumption figures, and even underlying architectures and yet were compatible with each other since they all used the same standard socket (LGA 775):
http://en.wikipedia.org/wiki/LGA_775I would have thought that ASICs are much simpler than general purpose CPUs, so compatibility issues would be less significant.
