Same reason I didn't buy a 1440 rez Dell when I originally bought the Cinema display: the Apple product is supposed to "integrate seamlessly, for a full cinema experience, and an orgasmic combination of fanboism". The display also made for a great MBP docking station back in the day. And it's still a nice display, if ten years old.

I want another one of those, only moar pixelz. And not five thousand g-ddamned dollars.

I have an Apple Thunderbolt Display and a generic 4k. The Apple display powers on instantly, the speakers are fantastic, it functions as a dock, and I can control brightness from the keyboard. The generic 4k display has none of those benefits, oh and I can't seem to get accurate colors.

I was prepared to buy a new Apple display today knowing that it would be quality in all those aspects. Instead it'll be trial and error to discover a good monitor that works as well as Apple's aging thunderbolt display.

I had the same frustrations, and found a way to control monitor brightness with the brightness keys:

https://www.reddit.com/r/mac/comments/6kj0oh/use_the_real_br...

Because 4K doesn’t pixel double and the 5K display selection is somewhere between sparse and nonexistent.

I have a recording studio with an iMac as the centerpiece. not buying from another company is really just a matter of aesthetics.