You must not be a scientist.

Gr-9s have quite the track record. I'm pretty sure your friend got a dud pair. That, or you and your friend don't know what grease is.

A lot of pedals have a break in period as well.

GR-9s are great pedals. My wife loves the hell out of them. I just don't find them to be very large foot friendly.

the bearing actually were too tight on my pair, but it is a two minute fix

I bought a pair of MKS Prime Sylvan Touring Pedals, which is supposed to their premium model, and the bearings were too tight on them as well. I adjusted them and they've been fine ever since. Perhaps it's normal with MKS to set their pedals that way. The dust caps were super tight and I almost couldn't get them off. If I didn't have the proper dust cap tool, they would have been ruined.

Usually a repack of new MKS pedals and you're golden.

It could have just been that. He still has them just sitting around. Maybe I'll check to see if loosening them a bit will help them roll smoother because giving them a flick with your hand they wouldn't even rotate around twice.
Still doesn't help the fact the machining is sloppy not that that effects how they ride