Hmm.. i can't see that passive style can be profitable at the long run. It also pretty unreasonable for me, because of many points. We have to be aggressive most time, but smart aggressive.
First of all because of fold
equity;
secondly because we don't want that our opponent buys his outs cheap and overrun us on a river;
and third, to isolate the opponent. Cause it's always easier to predict a hand range of one opponent in pot, as two for example and if there are three or more. Then it's more like fighting in the dark and most time you gonna be beat.
So it's kind of strange question to me, to be honest. What is better to be passive or aggressive? I would say, you can be tight or you can be loose, or something inbetween and it's okay if it fits your character and you still able to "switching the gears" and using your tight or loose image at the table to gain extra profits with unordinary moves. But you should be aggressive imho. Because passive play is most time weak play at poker (until you trap some other aggressive player with a monster) and passive players are weak players, like the "call stations" as best example.
That's why i always like to compare inequality between VPIP & PFR stats in my HUD. Already after like half hour playing with somebody, you can see roughly if he is a weak player or not. Even if you playing like 12 tables and simply have no time/concentration to watching how somebody played his hands. No matter if he loose or tight. But if the difference between VPIP & PFR is pretty big, it points on that, this is a weak player. And most time it is true.