I agree that hostels are fun for the reasons you said, but I've also gotten bed-bugs, I have shared a bunk with a dude who snored so loud he put ear plugs in his own ears.

I have been in a hostel with two scary ass dudes from a favela or something, luckily I wasn't the young, female solo-traveller they kept hitting on - literally: "kissy kissy?"

There are a million reasons to NOT stay at a hostel.