More P&O Budget cuts

I've written a few posts now on cruise lines cutting corners, making budget cuts or just, in my opinion, lowering the overall standard of the cruise. However some changes are just so small and petty that you're just left asking
"What's the point?"
Such is the case with the notification email I had from P&O this morning.




From winter 2012/2013 there will be a change to the in-flight bar service for all economy passengers travelling on our P&O Cruises Caribbean charter flights to/from Barbados. Passengers will now only receive 1 complimentary drink, either a glass of wine, a beer or a soft drink and all other drinks will be at a charge.  The airlines will have complimentary water on request but bottled water will be charged.

Why? How much money do P&O think this will save them? I could understand it if they'd had loads of complaints about drunk passengers on the flights but I've not heard anything like that at all. It's not even as though they can blame the airlines as it's their charter and if they wanted to offer free drinks they could.
What do you think? A justified measure to make your flight more enjoyable or just another cheap budget saving manoeuvre on the part of the cruise line?