It being 21 doesn't help anyone it just makes people buy it but illegally. But we have to to and complain to the state government because they control it, but if they lower it the Feds won't give as much money to the state as they are now so we have to get it lowered by every state for it to be really effective. Plus we're the people of America I think we should have more if a say than the government anyways.
There's little sense in spending massive amounts of resources on preventing something that is already happening and is largely impossible to stop. 21 year olds are not particularly responsible in many ways, and many older teens are very responsible. People who want to drink are going to do so, no reason to stop everyone, many of whom won't develop an addiction.
I believe that if you can go die for your country you should be able to drink. It is not like it is preventing kids from doing it anyways. I do believe that you are more responsible at 21, but when no matter what if your drinking, some of your responsibilities don't seem as important.
The drinking age does not need to be lowered. There is already enough issues with alcohol in this country that we don't need to add to it more by lowering the drinking age. Yes a lot of teenagers drink underage but the 21 law at least keeps some of them from drinking.