Seen this scenario play out in person several times.
Went to a college hoops game a few years ago at a neutral arena. However, one of the teams was sort of local and had a pretty big fan local fan base. Like 100 of their fans bought a block of tickets courtside directly in our view. They were the underdog and were sort of in the game early, so they started getting REALLY amped and jumping up for basically anything that could end up being a semi exciting play for their team. Any time someone tipped a pass, ATTEMPTED a 3 pointer or secured a rebound, the whole group lept to their feet like someone had just broken a backboard with a 360 dunk. It just brutal. Basically ruined the game.
Had another incident (different year, but same fan base) a few years earlier. Was sitting next to an older couple (probably in their 60's) and some 40 year old mouth breather and his teenage son were sitting in front of us. Dad was clearly a SUPER FAN and was standing for 75% of the game (again, we're talking a November pre-conference college hoops game at a neutral arena) and the kid started getting into it. The couple next to us poliitely asked them to sit down a couple of times early and they begrudgingly agreed. Finally in the 2nd half, the old man had had enough and pushed the kid back into his seat forcefully and said "Hey son, we cant' see!!". Dad turns around and screams "Sorry, #######. I STAND. I'm A FAN!!!!" and a minor brouhaha breaks out. No punches, but it was close.
You're buying a seat, not a space. In most cases, the expectation is that you sit for a majority of the game. Exceptions are big plays, the last 5 minutes of a game or if you're siting in a student/supporters section.