Most of the under 21 crowd that I knew throughout college had no sense of self control when it came to drinking. They were fresh out of their parents’ houses and wanted to do everything they weren’t allowed to do before. I’ve seen people puke all through the night. A major accomplishment was drinking to the point where you would black out. It was considered cool. I’ve seen them lose all sense of shame. At my old apartment complex we had to keep our windows shut on the weekends because the guys on the third floor would get so drunk they would piss over the side of the balcony and it would splash into our apartment. I’ve seen fights start simply because one guy said to the other “I bet I can kick your ass.”
Do I want these people able to drink in bars and clubs? Hell no! The bartenders and servers can’t or won’t pay attention to every one. With the age limit being 21 they have a few years of mellowing out before they can publicly drink. Maybe they might get a sense of limitation and self control. Until then they can do what most of the people around here do, try desperately to find some one of age to buy it for them which isn’t as easy to come by as you might think. Most of the 21&up that I know refuse to buy alcohol for anyone underage because of everything I’ve described in the first paragraph.