I wonder if dietary changes are just too difficult for doctors?  Or maybe just too costly to big pharma?  From the NY Times:

"Lower cholesterol doesn’t have to come from a pill.

Although cholesterol drugs are in the news lately, what is getting lost in the discussion is the fact that it’s possible to lower your cholesterol without drugs. It’s just not as easy.

In fact, many doctors think dietary changes are too difficult for most of their patients. While they typically encourage better eating and a diet low in saturated fat, they also prescribe cholesterol-lowering drugs called statins as a faster way to lower bad cholesterol.

But many people can’t tolerate statins and their side effects. Others simply don’t want to take a pill every day or shoulder the cost of a prescription. For those patients, dietary changes may be a better option."

http://well.blogs.nytimes.com/2008/01/23/eating-your-way-to-lower-cholesterol/?emc=eta1