Why? Because a lot of people are begging for a Mac Pro upgrade. Not a concept trashcan computer, not a thinner laptop. A serious computer for serious people who do serious work like video editing, special effects, running TV studios, high performance computing, chemical engineering, etc.

There are more useful attributes to a well-made desktop system than "shiny".

"Quiet" is a big one.

Not really.

The Mac Pro, while insanely quiet for what's inside of it, can't handle high resolution video production and graphics work. The fans peg and heat blasts out the top but the GPUs overheat at 130+ degrees and introduce artifacts into the finished media.

So in the end, the design is flawed. Which is a huge problem now that almost every production camera is 4k or higher now.

Liquid cooling in a PC case is near silent. And the GPU options are more powerful and have the right tools to stay cool. Only you have to put up with Windows which means locking driver versions, scheduling maintenance windows to upgrade edit bays and render machines and working closely with vendors for SAN and 10GbE options so everything keeps working.

My MacBookPro is considerably louder than my desktop (Windows) gaming PC with 6 fans in it. When the laptop gets hot, its a beast as far as noise (comparatively speaking, that is... its not going to disrupt a call or anything).

There are a lot of great quiet options in the PC building market right now, like PSUs that don't turn a fan at all under normal loads.

It is possible to build a PC or Hackintosh that is as quiet as a Mac Mini.

Replacing the stock heatsink with something that is overengineered for air (Phantecks , etc), results in minimal need for fan speed, and overall reduction in noise levels.

I like both, but "quiet" is not really much more important than "shiny" in a practical sense. It's just visual vs. auditory aesthetics.