This has been a relatively quiet time for me this year in terms of plane travel, probably only about 30 flights, an average year would be up to about 70 by now. Much of that is short haul business and pleasure in the UK. I could obviously exist without the alcohol but it's a small pleasure at the end of what are usually very long days. On those flights, I've never seen any problems with drink, there have been the usual % of rude dickheads, there are few children though on my last flight I had to tell the child and parent behind me off for kicking the seat.
I do think that some limit makes some sense, I well remember looking on askance at the mostly elderly demand for drink on the 8.00am to Barcelona. I fear that it is an unenforceable area though due to the vagueries of aviation law, and a suspicion that it is never going to apply on business class.