We know Apple didn't live up to their marketing promise (at least not so far, and at least not in the eyes of everyone). Doesn't seem like any kinds of sweeping or hiding of anything is really happening anywhere at all given that most people aren't finding these types of issues of much concern and don't see iOS 9 running like crap for them.
It's not really surprising that marketing paints things and sets expectations better than what they really are--happens pretty much with any product or service, and has bene happening for ages. It's also not surprising that initial releases of a new iOS version (or most other software) often have issues of one type or another, and often things get better and become quite good even in the latter updates (as has been the case with iOS 8 and iOS 7, to use very apt recent examples).
Not sure if rehashing same things that have multiple long threads saying the same exact things already helps anyone with anything, but it seems people like to have the same discussion over and over, even if it doesn't lead to anything new or different than the previous multiple ones.