Jumping in so I can hopefully help dispel this myth a bit. I'm a 2L student at Osgoode, and I've found the school to be one of the most welcoming, inclusive legal communities I've come across. The culture does change a bit year to year (imo), but in first year students generally stick to their sections and are understanding of the many stresses that pop up either individually or as a group. [By the way, when I say the culture changes, I generally mean that instead of bonding with your section, you generally start to branch out and spend more time with people who are interested in the same type of law as you.]
It can definitely be a hard program (just like any other law school, I'm sure) but I've found that the friends you make, whether it be section acquaintances or a solid friend group, want to help you rather than impede you as a competitor. For my section, it was very much of a "we're in it together" type mindset.
I don't know too much about York itself; I pretty much stick to Osgoode Chambers and the school, but in between the two there's a great communal vibe.