That makes sense. But I'd imagine that would bend the pins back quite a bit, far more than tiny globs of spit would be able connect. Maybe at first it'd be enough to make a difference, though, but I guess we'll never know until someone does a real experiment.
Also, in my experience it was only certain games that needed to be blown into. Some would work fine yet others I'd have to blow in like crazy. If the pins were bent back, it should effect all cartridges equally.