I recall that back when I was still using Windows (which was sometime in the XP days) opening the New menu could result in quite a bit of a pause, if you had lots of programs installed. It was really enfuriating, as the pause could be on the order of a second or more. IIRC I only used the New menu for creating folders, and creating some nested folder structure became an exercise in frustration.

I never understood how this could take so long but it seems the list of possible new filetypes was dynamically generated everytime by querying a dB of installed programs. Maybe it was so slow to encourage people to not use the new menu?