A few reasons have been previously discussed: plenty of diff viewers highlight non-standard characters being a big one, the other bit being if someone does see this error it seems entirely plausible as a
mistake.
Choosing something atypical in a way that is clearly trying to be invisible rather than being an accident will draw a lot more attention than “oops I must have typo’d it”
Comments
why bother with a . instead of a   or some other unicode hackdodgery?
A few reasons have been previously discussed: plenty of diff viewers highlight non-standard characters being a big one, the other bit being if someone does see this error it seems entirely plausible as a mistake.
Choosing something atypical in a way that is clearly trying to be invisible rather than being an accident will draw a lot more attention than “oops I must have typo’d it”