Clearly the big box consumer electronics store featured in last night's episode of Louie isn't Best Buy. The people here are wearing red shirts, not blue ones! And everything else is... well, okay, everything else is exactly the same.
Clearly Best Buy has plenty of problems that are out of any one person's control. But the fact that the incredibly unpleasant employee interaction at Louie's Not-Best Buy is so guttingly familiar sure speaks volumes.
And to answer the question, yes, most Blu-ray players are backwards compatible.