@pleonasm - In some cases people are in mobile homes because they need a cheap place to live, or because they don't want to waste money on room they don't need. They have no intention of moving the home around.
And even if they did, they could always just make the porch fully detachable. It could stay there, waiting for the home to return!
While I agree that weather can be a serious issue, I don't think anyone should not build something because of a few storms. They should just be sensible about it and follow local guidelines.
This is particularly important because your shoddy carpentry could easily affect your neighbors.
It's safest to just do it the right way.