Because they need to comply with laws in many nations.
Does the font matter for the ® registered trademark symbol?
10 Mar 2012
Select a font that allows the registered trademark symbol to be readable and legible. Most modern fonts include the registered trademark symbol, so you should not need to change fonts for the symbol.
Must you display the registered trademark symbol ® to afford protection?
8 Feb 2012
Yes. Displaying the registered trademark symbol ® provides actual notice and provides the ability to claim profits and damages in a later trademark enforcement lawsuit.
