Why should you scrub through a video timeline on your keyboard when you could manipulate it directly on the display? Many everyday activities, such as choosing emoji in Messages or playing music in iTunes, practically beg for direct finger input. This isn't to say that Apple's Touch Bar implementation is clunky. So far, it appears to be very thoughtful. It's just a perpetual reminder that there's a more direct way to meld touch with conventional computing, and Apple is passing up the opportunity.
Scrubbing through a video on the screen itself sounds frustrating and horrendously imprecise. Apple's solution with the touch bar makes so much more sense to me.
Apple passed up the "opportunity" to turn the macOS UX into a clunky, laggy, Frankenstein of an experience currently found on most Windows PCs. While you'd have to believe that Apple's got a touchscreen MacBook prototype sitting in a lab somewhere, it's clearly not a real product for good reason.
In all, the hate for the new MacBook, or even the previous generation of MacBooks for that matter, leaves me at a loss. My MacBook Pro from late 2014 can still wipe the floor with many of the best PC notebooks you can buy right now, let alone back when the machine was new. The people complaining at no end for a new laptop from Apple make me think that nothing the company would announce could have made them happy.