I know everyone complains about price but the product is really good, I think it's just part of the problem is People here just love to complain bat everything.
The biggest issue is just the location so it will always serve a small sub set of the population, that is a genuine concern. I live downtown, maybe a 10 minute walk from union and work in North York. So if I am travelling from home to airport I'll take it from work I'm back onto cabs or leaving car at airport. I've taken it 3 times so far and it's fine.
Just for Toronto price comparison, going to the Toronto Islands is like 8 bucks now and that is just for leisure - I was there yesterday no shortage of people going, so paying extra for an expensive plane ticket shouldn't in theory be a huge issue for most, the Go train to Mississauga round trip is 14 bucks now RT, uber to the airport from my place is 40-50, cabs are 65-80 (I think they make it up). Parking at the airport is about 15-20 bucks a day if you want your car covered less if you don't mind it outside plus gas of coarse.
I know someone mentioned the 2/person fee being paid to the airport, well we did privatize airports so no Matter what link was built airport was going to be paid.
I think prices may change to help increase ridership (it's been 50% on average for me) so if you can drop prices 10-15% and get 20% more People it makes sense.
I just wish people in this city stopped complaining about everything.