I get that you see it that way, but it's not legally revenue when the money goes through them to be filtered off to another company. Steam's revenue reports are theirs and do not include the money that developers get.
If they did it your way imagine how shit their profit margins in their reports would be if their earnings report showed they LOST $40 for every 3rd party game they sold. That's 100's of millions of loss every single quarter. That doesn't look good, and it's obvious that's not the way they do things.
No, because that $40 per game loss would be offset by the $60 dollars they bring in, leaving the profit (well, you still need to take off marketing / server costs / employee salaries etc.)
I own part of a small graphics design business - we sell printing to our clients, though we don't actually print anything ourselves, we outsource. The total money we receive from clients over the year is our revenue or turnover, the amount left after we take off what we've paid the printers plus our other costs & overheads is our profit.
In this instance we're the PSN equivalent and the printers are the 3rd party devs.