Drinking on public transport

So the government is to ban drinking on public transport.
Why do we need to do this? Is it because some people behave badly when they are drunk and upset some small minded people or is it because the government thinks it will show them cracking down on loutish behaviour.
If this sort of crap carries on I for one will not be voting for Labour at the next election. I have voted for them for the last 20 years but I'm getting sick of being told what to do by the state.