It's too bad we'll never know what would have happened under Jobs.
What annoys me is that for example Lenovo has 30 notebook models... so how much effort would it have been for Apple to release a laptop that accommodates real professional users a little bit, with, say: a 5th laptop option?
For those exceptions to the "almost" never—mostly IT people doing field support—they make a litany of adapters. Adapters make sense for this use-case: the target type of user already carries many in a "toolbox", and this is just adding on a few more.
And don't forget the Mac Pro. Apple's own internal "real professional users" are, as far as I know, more likely to use a Mac Pro at their desks and then a MacBook for mobile portability—but they won't bother to try to do work with the MacBook that'd be better done on the Mac Pro. Which includes plugging strange peripherals into it.