Can you drink and then drive? Sure.
Can you drink and take a speedboat out for a spin? Yep.
Can you drink and pilot an aircraft? Yessir.
Can you drink and carry a gun? No one is stopping you.
I suppose like everything else, it takes a level of personal responsibility. Each of these objects has the very real possibility of taking a life. Everyone should simply know their limits. If you believe you're OK doing any of these things after a beer or two, then by all means. Chances are, everything will be OK. Chances are, there will be no problems. But, I sincerely hope and pray that no one innocent gets hurt as a result.
For me, there is absolutely nothing important at all about drinking. That's why it was an easy decision for me to simply stop drinking altogether. (I will admit, I had a couple beers when I visited Disneyland in the People's Republik of Kalifornia, but I couldn't carry and wasn't driving at all, so no big deal there.) As far as intoxication is concerned, as a 6'5", 350lb male, I can tell a physiological difference in myself, after just one drink. I know I'm thinking a bit slower, my reflexes are a bit slower, and my entire thought process simply doesn't work as fast. Is this enough to make a difference? Maybe, maybe not. I choose to err on the side of caution.
Ask yourself, next time you have a drink, why you're doing it. Is it to relax? Is it because it's easier for you to socialize? Because you believe it has some sort of non-specific, and dubiously proven health benefit? Do you have difficulty giving a reason, beyond, "I just need it"? If this is you, it shows a level of chemical dependency on alcohol. I'm not saying you're an addict, or you need help, or anything like that, just that maybe you really don't need that drink.
My bottom line here is, be aware of what you're doing and what your limits are, and if it's really worth it.
You don't want to become Speedo boy!
http://www.youtube.com/watch?v=Kuuw8pT5ny0