While I can see what you're saying, out of all the bus systems ive ridden the TTC sure is strange about this.
Why not allow direct pedestrian access to bus loops? Is crossing a street with a bus route obtuse? Is crossing at an intersection while a bus might turn right entitled? Bus and pedestrian both have the right of way there and its up to good judgement not to collide.
All metro Vancouver stations and exchanges have no pedestrian restrictions, they often have a few crosswalks across the bus areas for better visibility. I understand that less risk of incident is better, but where do we draw the line? Especially if people are prone to doing it anyway.
The only big difference is that most TTC bus loops are fare paid, so I immediately assumed it was just a fare evasion thing. When I lived there, holding a metropass, I didn't think twice about walking right on into sheppard yonge when it was dead quiet, the few times I visited. I had paid my fare, and I looked both ways like any other street.