That number does not change, regardless of how severe the Captain tries to be. Thus, the issue is not one of punishment.
We DO, however, lose some very good Sailors because of it.
Some ask me why they are prevented from enjoying a beer now and then, even as they are charged with the defense of their country.
All I can tell them is that, when the issue was being decided, those most affected by it (their age group) failed to exercise another right: the right to vote, and to be heard. That age group was conspicuously silent when these opressive, foolish laws were being passed, as they are on most issues affecting them, to their regret.
While not taking a position pro-or-con, I encourage them to vote their conscience.
As for the "bloodbath" on the roads, the stats of highway deaths are virtually unchanged, so the removing of the rights of 18 -year olds was ineffective on that score, as predicted at the time by cooler, unemotional heads.
Let us remember, the ACT of drunken driving is a separete act than simply drinking, and is a crime regardless of age(and, BTW, the WORST offenders of which are in the 35-45 year old group).
The 21 year old drinking age makes NO sense, based upon the evidence and facts, which is why its proponents in the Nanny Busybody organizations use emotionalism and anecdotes to support the removal of citizen's rights that they support.
One crime, drunken driving, is NOT an excuse to criminalize a SEPARATE act, drinking with the wrong birthday. Either someone is at majority age, ALL THE WAY, or they are not. Anything else, IMHO, is unconstitutional denial of rights.