Unquestionably. If you recall, YouTube originally made its mark by having pirated copies of the SNL Lazy Sunday skit floating around, which quickly saw it become recognized it as the place to watch all kinds of pirated TV shows.
Eventually they started enforcing duration limits to quash people uploading entire episodes, but it wasn't until the content ID system was implemented that it started to see that type of content disappear and the 'homemade' stuff take over.
The home videos may have always been there, but it wasn't why people were using the service originally.