[dllthomas]

> I don't understand why 'i' has been given a pass.

Because it is well enough established (in both programming and mathematics) that it communicates literally no less information to the reader than "iterator" or "index" would in the same context.

> The argument boils down to saved keystrokes.

Not at all. I, for one, find it easier to see the shape of the whole expression when the variable names are shorter.

[kps]

Yes; prolixity yields clarity in programming about as much as in prose. The old quip needs an update: a modern programmer can write COBOL in any language.