I went to the first 20 or so festivals at Keith, and used to enjoy them greatly. Around the early 1990s, the type of behaviour described by Duncan McLean in his book became all too prevalent, and for that reason, I , and many other singers and musicians stopped going. I have no reason to disbelieve his account of what he encountered, and have no difficulty whatsoever in believing it to be accurate and unexaggerated. It needs to be emphasised that this behaviour is by the locals and not the singers and musicians who go to the festival to enjoy themselves. The problem is that they just don't get the chance. There is very little respect for Scotland's traditions, its' music or the players, although it has to be said in the festival's favour, that the concerts are always popular and well-attended, usually sold-out. The local committee do put in a lot of work for their festival, and deserve better from their community.
I can't comment on festivals south of the border, [ so it's a bit sweeping to ask "is this what a UK festival is like ?" ] but Mr. McLean's description rings true for several of the folk and traditional festivals in Scotland in the past few years, and that's from someone who's been to them.