Nilay Patel, writing for The Verge:
At the end of all this, it really just seems like Apple thought people were fine with the iMac and MacBook Pro, didn’t want to throw resources at the Mac Pro, and got blindsided by the reaction of their most loyal fans who depend on high-end Macs when the Pro lingered and the MacBook Pro was a little weirder and slightly more underpowered than expected. So the course was corrected, and here we are.
I would say that certain people at Apple thought everyone was fine with the iMac and MacBook Pro, but I would not say that it was everyone. If it’d been everyone, the Mac Pro would not have remained in its outdated form for so long on the store. What we have here is a tale of two different factions within Apple. The Cook faction wanted to kill the Mac Pro altogether, while the other faction wanted to remake it. Neither side prevailed until 2017, and then the right side won. And the right side won because the Cook faction finally saw “the reaction of their most loyal fans who depend on high-end Macs.”