This is untrue. Anyone who can afford a manufactured home can afford a home constructed to withstand hurricane force winds ... or without major structural damage.
Fact is, people want more square footage rather than well built. This is also true in site built homes. Quantity is almost always chosen over quality.
I see this decision making process occu every day. If it were not for codes (which are the minimum people should build to), I think most people would build the largest peice of %@#$ they could and not worry about structural soundness.
I feel for the victims too, I really do. But this myth that people can't afford safe homes is costing all of us more money (as the govenment bails out people time and time again).
Building codes for mobile/modular homes did increase in the early 90's. Old code required the home to withstand 90mph winds. The current standard requires 130mph. Most of the homes destroyed were older homes that didn't have to meet the newer codes. The average home built now has over $500 just in hurricane hardware (straps, buckets, clips, hold downs, etc) in it.