I can't really vouch for every part of the argument your acquaintance on Twitter, such that it's "mainly" made for commuting. Like I laid out earlier, it's more geared for business as clients and employers would be the ones expecting you to be in Toronto downtown by 9am for one reason or another. There are manager type of roles that need to travel as frequently as once a week between two cities, that's still commuting in my eyes. A Monday to Friday 9 hour round trip commute would be utterly insane, that's a quarter of your week gone. I'd have to be paid big bucks to put up with that.

Then again: One summer I did take a Via roundtrip every weekend (using a very nice pass deal at the time ofc) and I'd consider that commuting also.

Sidenote: In the morning Via in the corridor is very reliably on time. It's usually in the afternoon and evening when Via sees cascading delays by freight traffic.