Sounds like a dumb idea to me too..as did twitter and myspace.
Perhaps you read that in, erm, the article? The one you said you read?
Never underestimate the ability of a "dumb" idea to appeal to a massive market that just happens to not include you personally.
You seem threatened by someone succeeding at something that has absolutely nothing to do with you. It's really kinda weird.
Also, 40% of all women hardly sounds niche to me.