One of life's mysteries

Just back from seeing Elbow at the Hydro tonight, the music was great and we both enjoyed our first concert at this new Glasgow venue.
But. What is it about people at gigs these days. They're in and out the row several times for the loo and when they come back they have another pint in their hand, can't they work out the connection? Then we have the talkers. Two guys behind us talking loudly. I waited a few sets then I tapped one of them and asked them to stop talking. They started arguing with me saying I couldn't possibly hear them over the music. So I got the security chappie who asked them politely to quit their chat. As soon as he walked away they started again. Three woman nearby say to me that I'm quite right but as I pointed out to them no one backed me up. After an hour Mr B turned round and told them to shut up, they argued with him but got up and left. Result. I'm not a grump, I don't expect total silence, I just expect people who are at a gig are there because they want to listen to the music.