Because they are stupid and lazy. That's why they're called drive-bys.
The Aviation Business Gazette is a spam site mechanically generated from a publicly available database of pilots.
If you visit its home page, it appears to be a classic parked page. However, if you google site:aviation-business-gazette.com, you get thousands of cookie-cutter hits. It would appear the site's business model is to come up when a pilot's name is googled and hopefully garner some click revenue. It doesn't seem very successful in that regard. However, creating such a site is pretty cheap — all you need is the database, the article-writing script, and some space on a server somewhere.
I thought that was the case. But, I run AdBlock and NoScript, so it's unlikely I'll see any ads.
I do see the site tries to use googlesyndication.com, so I presume that would be loading ads if I allowed it.