I'll add a 3rd probability:
If they are the usual "partial rhythm section with singer" that seems to be called a band these days then they probably only play in 2 or maybe 3 keys 'cos E and A are "easier" on a guitar. They'll only know about 5 chords which will probably not even include 7th's let alone any colour tones above that...

Playing in one key all the time gets old very fast. You may not be noticing this consciously, but you're still noticing it.

IMHO such people aren't really *musicians, they're musical wannabe's.

/rant

* OK, maybe that's a bit harsh, but I've seen enough of it to know that a lot of groups like I've described are out there and they do not seem to develop any further.

--=-- My credo: If it's worth doing, it's worth overdoing - just ask my missus, she'll tell ya laugh --=--
You're only paranoid if you're wrong!