I have never stayed in a Youth Hostel, not that I had anything against them as such, but have heard a few too many unfavourable stories.
A pal was doing the pemrokeshire coast path and was staying at a hostel. At lights out time, the warden announced that he'd accidentally allowed too many people to book in and slung out the last person to arrive. Fair enough the overbooking was an honest mistake, but to sling someone out in the middle of the night in the middle of nowhere is outrageous. "I'm really sorry you'll have to make do with the sofa cushions" would have been a reasonable compromise surely?
I've known a few people back late and not being allowed in. Again fair enough if they've been out carousing in the pub, but one pal had had a logistical nightmare trying to bus back from another town with a mended motorcycle wheel then ended up sleeping in a phone box.
I seem to remember they no longer allow actual " youth" to stay unless their accompanied by an adult, which kind of defeats the point