That "only" reason is a valid one......if you feel your car or truck has a fragile useless engine you should swap it out for one of these 2 strokes----then open a business doing conversions for all the others that made the same mistake......you should be rich if you're rightThe pollution issue is the ONLY reason two stroke engines are not everywhere.
I think any four stroke that could compete equally with a two stroke would be so expensive and fragile as to be useless.