Any button assignment also must have a keyboard shortcut.
Which begs the question, should we be promoting users to have to look away from the screen instead of doing a normal shortcut? What difference really is there of F1 favouriting a topic vs a touch bar icon which has a save topic icon?
I don’t like the idea of a feature on a “pro” machine being really for people unfamiliar with application short cuts.
Physical keys are also easier to feel out and press accurately without looking at your keyboard vs pressing an icon on a strip.
I see your point, but the flaw in that logic is that Apple isn't looking to
replace keyboard shortcuts with the Touch Bar, they aim to
supplement them (among other things). If you're 100% familiar with a certain keyboard shortcut, then sure, it's usually faster and more convenient to press that keyboard shortcut and to do it blindly, instead of having to look down onto the Touch Bar.
But do you know every single shortcut in every single app you're regularly using? This is a genuine question because I most certainly don't, and I consider myself fairly well-versed in my daily driver apps. There are plenty of features that are tucked away in the menubar or in submenus that I need to hunt down because I either don't know the shortcut from the top of my mind or because it doesn't have one (and I know you can set custom shortcuts, but this isn't a real solution for every niche feature that you use on occasion, and it will also increase the forest of keyboard shortcuts that you have to remember).
Even worse, the average user might not even know of many of these hidden-away but useful features because he doesn't go explore the menubar into each little submenu in every new app he installs. Keyboard shortcuts help you with actions that you perform regularly, they don't help with the discoverability of new features. For example, I've only discovered a few months ago that iOS has a built-in, fully-fledged and actually really capable document scanner, simply because I didn't expect such feature to be hidden in a tiny submenu in the Notes app. And I've seen plenty of complaints about for example how obscure-to-figure-out some 3D Touch features are.
The Touch Bar helps with all of those things, it brings forward features and options that in the context of what's on-screen make sense to perform so you don't have to go hunting for them through some tedious menus. If you're going to perform an action frequently, then sure, you can learn the keyboard shortcut for it, the Touch Bar isn't stopping you from doing that. But for all those times where you
don't know what button combination to press for a certain action, or even that a useful feature
exists at all, I'd argue that the shortcuts of the Touch Bar are far from useless.