Why YSK this is that some of the soap absorbs into the fruit, especially berries, and let’s say you are washing your cherries with dish soap, and you eat them. That story ends with a long bathroom trip as soap makes you a little queasy. ETA: Nobody has heard about this?! I see it in the southeast where I live.
I’ve always done it that way and was never told otherwise by anyone until about a year ago when my gf saw me do it. I never had any issues either, I’ll still do it sometimes if I can get away with it.