So why don't they just say something like "we are committed to the Mac Pro and OSX for at least the next xx years, but it will evolve to allow our commercial customers to evolve with us" or "we will move away from the high-end markets towards the consumer as that is clearly where the big bucks are." Then we can all get on with our work.
Because no company is going to invest in a "dead computer line walking." It also is not going to make a long term commitment b/c sales could drop off; it needs flexibility. 9 to 5 Mac has a YouTube video posted of a guy editing a 4K video on a MacBook Air w/ TB and Red Rocket card, so the MP's death could be a lot closer than even Apple realizes. Many suspect Apple will, in fact, release one more MP and done.