Suppose I answer a question in one forum, then move on to another, and find that there's an identical post there, where someone else has already answered it in a similar answer. This means that I would have entirely wasted my time (or the other person answering would have wasted THEIR time)
The posting "shotgun" approach is just not very considerate of other's time...
"Lisa, in this house, we obey the laws of thermodynamics!" - Homer Simpson
"I have my standards. They may be low, but I have them!" - Bette Middler
"It's a book about a Spanish guy named Manual. You should read it." - Dilbert