Why are automobile manufacturers trying to kill the stereo aftermarket?

Tell me about it. I've been looking into buying a new car, but finding one with two DIN slots is damn near impossible. Heck, even ONE din slot is too much asked these days.
Practically ALL brands are now shipping their newest cars with factory installed HU's.
And what pieces of cr*p they are too. Most of the time not able to produce more that 4x15 watts. The produced sound of course is what is expected : crap.

Last week I went to a BMW dealer and the first thing I did when I looked into the car was ask if there was a possibility to rip that POS HU out. The salesperson looked at me as if I had said a dirty word. "Sir, it has taken them 10 years to actually implement a car stereo into their cars, and now you're asking me if I can sell you one WITHOUT?"
"I sure do, and so should everybody who has even the slightest respect for the quality of the sound they're listening to !"
Well, that guy wasn't happy I can tell you!

The worst kind of factory HU's are the ones that don't even have a display anymore, but their display is being shown by a separate screen mostly on top of the dash. Those are really the pits, since ripping those out would mean you'll also render that screen useless. (most of the times that screen also functions as display for the cars own computer, which shows gas levels etc.)

Fortunately, some aftermarket solutions are available for this too, but only very few (like this company who makes adapter for aftermarket Sony HU's.)

This is a really, really, really bad trend and I hope to see it end real soon now. (but I'm not holding my breath)