I always want to walk up and ask the wanker: "so.....um........what song would that actually fit in with?
These guys are looking for some flash or some hook to draw viewers in. It's difficult to do something on your own, with a bass, that is harmonically interesting. Even a top player will tell you that. Bass is an ensemble instrument. Slap is easy. Hence, a lot of players go for the quick and flashy option of slapping like mad in E.
I thought Ken Smith had the right idea, I recall reading that he had banned slap in open keys at his trade show stalls. I've practiced slap in many keys but like everyone else, I'll readily admit I'm strongest in E!
I'd love to hear more bass and amp reviews use the gear in a mix with a proper song or backing track. Playing with other instruments is much more revealing than solely focusing on how the bass sounds on it's own.

