Nomorecatering, I'd suggest we're more on the same page than you think. When I mentioned that multi-engine/IFR instructing counts more than bashing around the circuit in a single, I did not mean to imply that one is any less a "pilot in command" just because he/she is flying a C152. I'm simply saying that a couple of thousand hours of multi-engine/IFR instructing will make you much more attractive to an airline employer than the other kind. That's just the way it is.
It's been a few years now since I did any kind of instructing, & even more since I flew any kind of single-engine bugsmasher. If I were to jump into a lightie tomorrow, I'd probably be dangerous. It's a different kind of flying, requiring different skills that I just haven't practiced for quite some time. Airline pilots are no better than any other kind of pilot; they just worked hard & got lucky - a fact that is often lost amongst some in this industry who think that because they now fly jets, they're better than everyone else.