Apple cannibalizes their product lines in favor of what they want to push, and it feels, given the steady disregard of the Mac over the last ~3 years, that they want to push iPads. A touchscreen doesn't make sense for a Mac because they make it not make sense for a Mac, yeah?

(I'm not even saying they should have one. I don't care either way. Just that the Touch Bar is not a good replacement.)