I disagree. Perhaps because my mind is too nerdy to see the inconsistency
When selecting words by double clicking, keyboard shortcuts, or finding them with the Find/Replace window, Papyrus needs to decide where a word starts and where it ends. This is usually done by internally defining ranges of characters that can be in a word (letters, hyphen, apostrophe), characters that are in-between words (white space such as space, nonbreaking space, line ends, paragraph ends, page breaks, tabulators, etc.) and punctuation (dots, commas, colons, semicolons, quotes, dashes, etc.).
If you are searching for a semicolon without the »whole word« option, Papyrus will find the single character that you asked for. If you check the »whole word« option, Papyrus cannot find it because the semicolon is not in the group of characters that are permitted in a word.
I think the »whole word« option is primarily intended for languages in which words can be used on their own or in composite words. Remember that Papyrus was developed in Germany where this happens very frequently.