I respectfully disagree. In normal typing, I don't consider a capital "I" to be significantly more taxing than a lowercase "i". Relatedly, I think there's a reason that I've never heard an argument about why we should prefer square brackets over parentheses (square brackets require no shift while parentheses do).

Right off the bat, I notice that when I'm quoting something using double quotes or placing something in parentheses or curly braces, I don't even have to think about pressing shift. I type them just as quickly as any other punctuation. So I don't think there's much validity to this argument based solely on keystrokes.

On /some/ keyboard layouts that may be true, but remember, on different layouts, you get different results.

On German layout, for example, `:` is on `Shift` + `.` – and therefore just as easy to use as `.`

(Sorry for the formatting, but this damn page doesn’t have any useful formatting syntax, or escaping. If you want to enjoy the formatting properly, just use a userscript to run a markdown parser over this page).