Absolutely this. I was in the business for years and it's nearly always the drums and a guitar. 9 times out of 10 all I can do is try to get the vocals above the stage volume and add a little balance. Usually, the drums and guitar aren't even in the mix... And that doesn't even count the "I need more in the monitors". Get in-ears, lose the amps and if the drummer doesn't know how to drum without beating the tar out of the drums, then gobo them (or go electronic) - especially if you are playing small spaces. THEN blame the sound guy if it's still too much. Also - yes, you aren't playing a concert so play accordingly.As a music fan, loud is fine at a concert where the band is the main focus and reason for being there, and the sound is good and not painfully harsh. Not fine if I'm eating dinner and can't talk to my friends. Sounds like a bit of a mismatch in your situation.
Could it be that the FOH guy was balancing the sound and vocals to the loud guitars coming off the stage? It's a tricky situation for FOH when the drums and amps on the stage are overpowering the room/PA. You can either ask the players to turn down and hope they're not crybabies, or just let it be. I've done live sound before, and I'd ask players to turn down if they were too loud off the stage, but some guys just won't because "that's my sound, dude!". Unfortunately, some people just don't get it and never will.