Rope Trick and Handy Haversack

By this logic, why couldn't a PC place a portable hole (or even a handy haver sack, or a bag of holding) inside a handy haver sack (or bag of holding, or portable hole, etc) - so long as they do not open the second bag while it is still within the first bag?

Many DMs seem to ignore encumbrance anyway, so why worry about how many bags of holding are within their (main) bag of holding? I would just rule that if they attempted to open one whilst it was within another a "BAD THING" would happen, but otherwise they were fine - and would need a standard action or move action to remove the bag 1 from within bag 2 and then open it. As a swift action they could, of course, flip open the top of one, reach in, and flip up the top of another - and suffer the consequences, of course. On the other hand, perhaps there are times when they wouldn't mind being randomly plane shifted due to the resulting planar rift . . . .