Ticket prices.

[Will]

I've been to 2 games at BMO Field and they do have some decent variety for food. Probably better than the Rogers Centre. Prices are probably a little better at the Rogers Centre though and you can bring in outside food to the Rogers Centre so that's a huge plus. Beer selection is better at the Rogers Centre. Payment options are also better at the Rogers Centre.

The Rogers Centre also has more and better restaurants near by.

You do raise a good point. People are probably a little more likelier to purchase food & drink at BMO due to its immediate surroundings rather than Rogers Centre. There are restaurants in Liberty Village, but not to the point of Rogers Centre.

However, might I suggest that the merits of concessions at BMO vs. Rogers Centre has little to do with the subject as presented by the OP.