Apple is used to getting blowback; it is not unusual, and it is sometimes warranted. When it is, later models address the complaints.
I mean, just compare the initial reaction to the very first MacBook Air, to how people feel about that model line now.
It is way too early to know how the new MacBook is going to do. It's way too early to know if the Touch Bar is better UI than function keys.
It's not early, most things in UI design are actually very scientific and can predict in advance how fast you can use something. Basically touch bar is harder if not impossible to use without thinking and looking because it breaks consistency and is also slower to use because targets are smaller, i.e. you have to be more careful not to touch other targets, etc.
Most users can't touch-type the function keys, so having to look isn't much of a departure for the vast majority of their audience.
I cannot say whether Apple have designed and rigorously tested the Touch Bar with UX in mind but they do have a fairly strong reputation for doing such in the past.