Yes, and they don't need to spend lots on expensive kit, just pay a few more people to do it.
I've said all along that it is to get people to turn up early, get inside early, and then buy their expensive shite food and drink, so for me its wholly commercial reasons, hidden behind security because that was convenient. People are far more vulnerable queuing outside, than they are inside, so you tell me why you think that its security.
Funnily enough tonight at M1, it was a huge queue, but very efficiently dealt with and took us just 5 minutes to get in, the complete opposite of Saturday I'm told.