Actually I suspect the real answer is: Because it's not as much fun.

S3stat pays my rent, and it took a weekend to build. It's dead boring, but there's a market for it so people pay money.

Blogabond is still fun to play with 4 years in, was technically hard when I built it, and thousands of people use it and love it. When I tried putting ads on it, it brought in maybe two bucks a day.

So yeah, boring stuff makes you money, even if it's not that difficult.