It was in the late 80s I was running a gate with a security crew (untrained thugs on speed) who just wanted to beat people up and there was little or nothing that could be done to stop them. At least they weren't robbing people or scamming tickets, as other crews were doing on other gates. Around then was the only time I've ever had to deal with someone who'd been knifed. That was when there were rows of people along the main paths and at the bridges yelling 'black hash', while behind them, not very discreetly, were groups of big blokes with pickaxe handles and dogs. Stallholders were being run by protection rackets and there was at least one incident when someone was driving around site with a gun.
Yes there was more 'edge' in those days, but let's not get too misty eyed about how good it was. Plenty of people (inc my beloved) stopped going because it had become too heavy and drifted far away from the 70s/early 80s vibe.
As for 'professional hippies' and their arts, your memory is playing tricks. They've been there since the beginning