Basically he is saying some of the things on the post are not a niche anymore. What he should be saying is that he thinks some of the things on the list, specifically making money online, is over saturated and is no longer worth pursuing.
But I disagree with him. I have searched all over the place for making money online stuff and I read literally hundreds of blogs and I never quit, I still read them. I find new blogs every week, and I read those also. Making Money Online will only increase in popularity due to the trashy economy and high unemployment rates.
Steven here, my friends.
Believe in God.