There are 7 billion people alive today. It's silly to assume otherwise.

What's more is that it prevents learning. I was talking with friend of mine the other day about an idea to set up a sqlite database with a html/css/javascript front end in order to organize all the word documents and spreadsheets that currently are haphazardly tossed onto a shared drive at work.

He pointed out that that's basically a content management system, and I realized that up until that point I assumed I was the first person to ever think about this problem. Now I have a bunch of people's code to read and learn from.

It may be true but it's also rude, just like calling a fat person "fat" is probably truthful but rude and not very helpful to say in most conversations. tylermenezes used the phrase as an appeal to authority in order to demean the notatoad's argument. I don't think your example compares to that case (shutting down trains of thought vs. re-inventing wheels).