I thought Vegas had the worst crowds here in the US, then I went and saw APC at the Hollywood Bowl last year. GF (now wife) and me got yelled at for standing up when APC came on. That crowd was fucking awful. We were in the middle of the venue and could whisper to each other during the show- all while hearing other conversations.
The HB was a great venue, but fuck that crowd. Only other LA show I was at was LITS at the Forum. About 1/3rd of the venue was empty but don’t recall the crowd being complete butt (was a bit sterile, and that was before the renovation so the place looked and felt like a tunnel with bad lighting).