[nights, again] To be honest, I don't think that what you say has ever been true, at least not for the last 15 years or so. I think there's a whole bunch of myths that get irresponsibly perpetuated by ex-students about how all they did was drink, get laid and engage in oh-so-hilarious traffic-furniture relocation exercises. Though now I think about it...
My gripe about assessment, apart from the obvious selfish one, is that for all the foreplay and aftermath that surrounds a formal exam is that, per hour of examination, I estimate you lose about one weeks' worth of time that could be used teaching people something. I'm still "out" on continuous assessment. I hated it as a student, but now I'm on "the other side" I've seen evidence that it can boost the performance of those in the bulk of the distribution. The lower end is always impossible to motivate, and the top end usually looks after itself but I do worry that if things become too prescribed they might get a bit bored. Personally, I advocate oral examinations since they give people the opportunity to reveal what they know, rather than what they don't. However, I realise most people feel quite intimidated by them so my feeling is that a mixture of sit-down, continuous assessment and scary viva would probably be the fairest system of all.