They probably don't consider the 300 a luxury car, although it has all the right things it doesn't have the brand status OR the "quality" for it, ya know, gathered leather and padded vinyl all over the place. Oh yeah, and more fake wood
Okay, just kidding
Really though, that list is a joke - and if you consider the TL a luxury car, the 300 is too. In fact, the 300C makes much more of a luxury car than the TL does, for many reasons (or features!), more power, and a traditional RWD setup vs the TL which was a gussied up Accord (with a different body!)
That and we're talking about Acura here, they're known for rattles and tranny issues about as much as any other car company is. Their seats may just be a
little nicer and the dash too, but it's not going to be that big a difference, certainly not worth it!