I too am frustrated with the high level of inaccurate genealogical information on line. What is even more frustrating is that when you notify the people about the errors you are ignored. Recently I found a tree where the daughter was born 30 years before the parents. I could see the mistake happening but it should have been quickly be corrected.
Another example of this situation is shown with my 3rd great grandmother. She was married and lived in Binghampton New York in the first couple of decades of the 1800's. There are those who have her associated with a lady in England who lived at the same time. The error is apparent when you trace the English lady and find she is in England during the time my 3rg grandmother was having children in New York. To make the two ladies match you must assume that she had a baby in the US, and made a round trip of 8 to ten weeks each way to England in the two years between her children births. Of course I heard one newscaster refer to these sailing vessels as Cruise Ship, so maybe I am being to hard on their ignorance.
I think, like you, that people see similar names and don't stop and realize there are at least several thousand people with that name at any one time.
Whether it helps or not, when I find errors in peoples trees I have started adding comments that state "This tree is in Error and then give the correct information. I also volunteer to provide the sources for my information. Interestingly no one has asked me for copies of the correct information.