What you are saying is true, but it's also worth keeping in mind that the 8086 was already three years old by the time the first IBM showed up, and the 286 was launched only a few months after the IBM PC.
That was part of the reason why the 286 ended up with the "braindead chip" reputation - it was designed before the IBM PC and DOS showed up, and thus the inability to easily switch between real and protected mode was not seen as a big problem at the time it was designed.