In many cases
Past experience has shown that in a lot of cases, those who stumble upon these type of finds, are not necessarily in a position to appreciate what they have found, nor it's real value.
Then when the info is posted, a zillion people want in on the deal. This gentlemen has already half a dozen ( the same day ) offers to take this a little further.
In my opinion it all comes back to the " snooze and loose " thingy.
Stepinwolf