I know in my case that up until 2 1/2 years ago, Grandma Bates was just that to me. I didn't know her first name or her maiden name, nothing, nada...but I knew she was my Grandma. I created her WikiTree profile, stated all that in it.
Someone, a wonderful WikiTree person helped me find her first name, but all of the documentation I was finding didn't match what I had been told about her, so the profile still had no sources for over a year. With what little information that was in there, a second cousin, once removed found me through that profile and sent me a slew (24 pages) of information on Grandma Bates (who really never was a Bates to begin with), and also with that information came a ton of sources (and it turned out that the documentation that I had found and was smart enough to save when first found) turned that profile into a completely sourced profile.
So in my humble opinion, a profile with no sources, can at times have value...but that's from my experienced.