Surely some are exagerrateing or counting anything with a .blend* extension.
I have 14 blender project files. Each of those may contain anywhere from 20 to 100 seperate files (.blend1, .blend2, .blend3, etc… etc… etc…). But then again some just download anything that ends with .blend and store it on their harddrive, whether they made it or not. So just asking how many blend files someone has is no relevance to skill or dedication. It could simply mean some is obsessed, or simply has nothing better to do.
I think a better question would be, how many blender projects do you have?