policy is the least they can do. if you're being a jerk and the want to get rid of you, they can quote policy. if they want to help, they can.
Employees may be empowered but that doesn't mean they'll help. It's a lot of trouble to take your TV off the wall, get all the accessories together, and cart it in to the store. If the employee on duty doesn't feel like helping, you're out of luck.
And naturally, if they are offended or upset at the product too (ads?! after you bought it?!), they may become your advocate... and go well beyond just being nice and helpful.
This works for isolated issues because they are isolated issues.
and then when they make their next round of stocking decisions, they're looking at vizio return rates and negotiating accordingly - either ordering less product, or requesting lower prices.