Yeast kidnapping #2: why not to do it

I found out why using your stash of homebrew as a yeast bank, as proposed below, is a bad idea. When you bottle some beer, most of the yeast should have settled at the bottom of the fermenting vessel, so what is in suspension is the least flocculant of it, and this yeast is what goes into the bottle. If you then drink that beer and culture the yeast up, you have a strain which is slightly less flocculant than what you had before, and you're effectively breeding the flocculancy out of the yeast.