Yea...um, so show me a single competitor that uses hard plastic like that in a ~30k "luxury" car. "Better" than LeSabre still isn't good enough. The competition and points of reference aren't with GM's past models, but rather other manufacturers. Now, here are some reasons why the use of hard plastic does affect daily enjoyment of the car (or will soon after buying):
Rattles. Plastic rattles, especially if the roads are full of potholes. Rattles will develop with dash panels.
Safety. In an accident, if your head were to fly forward, would you rather hit a padded vinyl or hard plastic? Yea, that's what I thought...
Quality. It just doesn't seem as high of quality when you know that GM and Buick cheaped out on the dash to cut costs. I've said this before and I'll say it again: if a manufacturer is going to cut costs and cheap out, the manufacturer should only do so on parts the consumer will have LITTLE TO NO CONTACT with. No one is going to care about the material underneath the dash at the back of the footwells, no one cares if the floor carpeting extends under the front seats (or if there's a plastic tray there instead), no one cares if the trunk liner is of high quality materials (as long as it isn't obviously crappy-looking) and no one cares if the glovebox is lighted/made of excellent materials because the only thing that will fit in there is the owner's manual. But people do start to care when there's this big hunk of cheap hard plastic staring at them from the dash every day. Again, find a competitor's vehicle that has a huge plastic dash like the Lucerne's.
To make sure everyone's on the same page...