The problem is, there's less people willing to work for the money. The quality used to be better, because everything wasn't quite as expensive; and those that worked there were generally very young and working that job could actually get them what they wanted/need especially upon moving out at 18. The problem now is that most people, at least in the US do not move out at 18 and in a lot of towns you cannot afford a place(Even an apartment) on one persons wage. There was also a lot more respect in the workplace, and a lot of it was more professional and less relaxed. You were expected to perform at these levels no matter what you're being paid, the problem is now it's hard to find people for as many locations as there is.
You can take Wal-mart for example as well, despite being so huge; people would agree you usually get lesser service from the people that work there. People want more pay, simply because things are more expensive; and if they can't get what they need first and foremost with that job they're not going to care nearly as much.
Another thing is, employers are generally scared to fire people due to bad press; people LOVE to pick on the big companies for every little thing. "How could they fire this person with a disability!" Or You see headlines of racist allegations or some other, which is why you will see tons of people that don't care/are terrible workers.