A possibility of the above - a recent huge thread here on PPRuNe about the Stansted security staff being rude and jobsworth in comparison to other bases was followed by an improvement and it would be nice to think things were connected.
However, BSA (British Shopping Authority) unfortunately have an approach of contracting out everything they can think of, and then feeling that the management task is done apart from regular financial reviews that costs are below budget or revenues above.
There's a current management ethos that in service industries money spent on providing a "good" product, whether in supervision or product provided, is money wasted because it doesn't contribute to the bottom line this year. Impact on future years is ignored as those involved hope to be up and away with their bonuses by then.
And it's not just confined to the low costs end. A recent discussion on another Frequent Flier website was concerned with how standards in the BA Concorde Lounge, for F passengers at Heathrow T4, have fallen way down in recent times.
Part of the Stansted problem is the large number of low cost tickets sold for early departure (0600 - 0730) for whom no effective reasonable-priced accommodation is available. Even if you stay in Central London the one hour train journey at that hour (by trains departing from Liverpool Street before the London Underground is up and running to get you there), the low-cost carriers' long check-in times and "lose it if you're late" attitude, and the scheduling of large numbers of based aircraft to depart very early in the morning, all leads to this shanty-town atmosphere.
But I agree there is no excuse for having to negotiate mounds of uncleared food-strewn crockery and cutlery all over the floor at 0600 in the Stansted departure lounge. Except that no one has bothered to have any staff on duty to clear it, and even if there were there would certainly be no management on duty to supervise them (which therefore amounts to the same thing).