Was translating a very old Pascal program. My editor didn't have syntax highlighting for it. Spent a couple hours translating a very large function. Wasn't until I finished that I realized it was wrapped in a very large block comment.
That, and most decent editors have a "comment current selection" feature that makes single-line comments easy enough.
* color blindness
* broken syntax above typically throws-off subsequent highlighting
* touch a lot of embedded stuff where having any kind of editor at all (even without highlighting) is a luxuryPersonally I like having two block comment syntaxes to choose from, like Pascal's { } and (* * ); normal comments use { }, while if you want to comment out an entire block of the program and not have the comment terminate early, use (* and * ).
Most of my professional life editing Pascal code was done from command-line editors that didn't have support for commenting the current selection, other than piping the selection through a command like sed. I appreciated being able to narrow down bugs using (* and *).