Isn't that why there are supporter sections now for this malarky? It can't be argued it creates atmosphere, it can be argued whether it's the best way to do it and the most beneficial.
I remember going to my first roughriders game after moving over being fearful of not knowing some of the rules and how the game worked and being shown up for the amateur I was. Took 5 minutes to realise at least 50% of the crowd a) had no clue about the rule or what was going on in the game b) were there just to party and get drunk. It's why the crowd herding "cheer now" signs work so well to create atmosphere. As artificial as it comes and coming from the UK I hate that. It is effective.
I understand the two lines of thought;
a) when you pay your hard earned money out to watch it's your right to enjoy the experience however you want.
b) You are there to support the team leave the antics until before or after, during half time or breaks, show the team you understand the play.
I think there is a time and place and things like flags, drums/instruments (shudders - not really sold). Supporter areas do add to the atmosphere and can spur on the team but also add to the spectacle for cameras, new fans or people coming into the sport. As long as that is not impacting other peoples enjoyment I get it. If you don't like it you its like this forum, you don't have to read my stupid ass essays or react to them just ignore it or sit in a different section.
I'm similar to SthMelbRed in enjoying watching and trying to analyze the game and joining in with chants etc. as the come. I wouldn't want to be waving flags around in the game and it would peeve me if it was happening around me and impeded my view. Again though keep it to certain sections or during certain periods of the match day, or simply sit in a section that doesn't happen when you book tickets.
Both can create completely different atmospheres too. A whole stadium intently watching, seeing the play rise and drop in intensity, reacting to play and passes is a cool and unique unity of people. The Riders experience creates a fun party atmosphere but can take away from the game if overdone.
Likewise they can affect the players differently. I'd think there is more pressure on the players shoulders and certainly more celebration when the fans are invested but that can also be too much for players sometimes. The party atmosphere might take a bit of weight of the players shoulders but also allow them to concentrate more?