Yes, many of us have posted here before about this rudeness. Stansted houses the greatest proportion of jobsworths and burger-flipper rejects of any UK airport.
But just down the road, at London City, the opposite applies. Pleasant, efficient and good at their job. What's the difference? I can't believe they are paid vastly more for the same job, so it must come down to management. And as with any structural management issue, endemic problems lower down can usually be traced to the top.
Time for the airport manager (and whoever devises the unique security hassles there) to consider their position. Or have it considered for them.