Just one reason why I shoot 4/3'rds.....

I think you are right; at least that is what people told me who had both Olympus and Canon DSLR cameras.  But since I leave the lenses on the Canon DSLR cameras (as I have done for a number of years even with my Olympus DSLR cameras), that appears to reduce any dust problems that might develop.  That was the only weakness that I could find, when I decided to use another brand.  Some people have learned to clean the sensor themselves and apparently do it well on a regular basis.  Some others just pay for having them cleaned by a professional photography service center.

So...yes...using what some consider to be the best dust removal system is one reason to stay shooting with your Olympus 4/3rds cameras.