Sure it's optimal to work linearly, but in the real world things come up. Now if you are looking for a reason to tell stakeholders to suck it up and wait, then poor branching support may help you, but that's a technical solution to a managerial problem. If you're interested in having the most flexibility to solve real world problems, then git's power is indispensable. Hell, you can work linearly all the time, and retroactively convert anything into a branch. Even if you don't need branches. Even if you are the sole developer.
Sorry if that's a little harsh, but statements like "My point is, if you want lightening fast rev control for some reason, probably better to not use distributed." smack of willful ignorance. Go use git for a while and then come back and try to say that with a straight face.