To be fair it's the combination of the hardware and software. There have been plenty of glitches that were exclusive to the new phones like the rattling cameras. If you wait a little bit these things get fixed. Yes there's no guarantee but at least you can hear about others' experiences before you jump in. I agree overall that it's a software problem. But I also understand not being happy when you spend your money to upgrade to something that has issues/worse performance that you didn't have before.First of all, you can buy it on day 1 or day 428, you still won't have any guaranty that they will deliver quality software.
Second of all, quality software is... software. You might want to talk about iOS, not the iPhone.