Let me get this straight.
It's better to completely isolate genres at gigs than to mix them up? That's like saying new bands shouldn't gig with established bands, coz what if they're shit? They may as well be playing a style of music you don't like.
Other than metal and booze, the major theme of gigs is socialising (how many people actually watch every single bands' entire set?). So I see a mix up of genres a good way of having a piss break and a chat with your mates when a band you dont like is on, while the real fans can do their little dances in the pit.
As for Macabre taking up a million dollar deal, aside from the established fact that they would never be offered, they wouldn't take it. They're not Metallica, they don't need the money, they don't take themselves that seriously and they've been pretty successful at plodding along for the last 20 + years without a mainstream audience for support. Coz who needs it, right? Oh....