This is an example of 'FourSingleQuotes' -- Pretty nasty, as you can see. Wiki parses FourSingleQuotes as:
ThreeSingleQuotes + "'" + "text" + ThreeSingleQuotes + "'"
As a result, the first printed single quote is shown with strong emphasis and the last printed single quote is shown as normal text.
If you want to concatenate two words without creating a WikiName, better use SixSingleQuotes (see there for a reason why). To provide moderate emphasis for a word or phrase, use TwoSingleQuotes and to provide strong emphasis use ThreeSingleQuotes or FiveSingleQuotes.
See also: TwoSingleQuotes, ThreeSingleQuotes, FiveSingleQuotes, SixSingleQuotes