Damn. I'm just really glad to know I'm not the only one.
One of my company's biggest sellers is a tool that does web scraping. And since we charge a monthly fee for it (I don't think most people realize that our server fees alone run nearly $2,000 a month for this, and that's with amazing deals on web hosting), we get a lot of "Pfft--how hard could that really be to build?"
The answer is: It's easy--if you're only scraping one site, in small quantities. The minute you try to implement in Unicode (we have) or bundle it all in a report, or keep an ongoing cache of what your scraper found, or heck, scale it to millions of scrapes per month, all cached and indexed--now you are looking at something difficult.
We have a talented team, we're 16 months into this, and we've since seen competitors pop up all over the place. They all get a few customers and then run into scaling issues. It's one of those markets that seems seductively easy, but really isn't. And since there are many competitors lowballing, we've had to focus even more development time on awesome features to stay ahead of the curve.
I wish articles like this woke people up. Unfortunately, once you're committed and have a few customers, it's easy to rationalize going deeper. But web scraping can be a tricky industry to turn a profit in, especially if you are relying on a small and fickle customer base.