Price is usually the deciding factor in what engine to use, when building new machines. Same holds true in lots of other manufacturing venues. After all, a Dollar saved on each machine, or whatever the product is, and you are building 10,000 machines, is quite a sum. It all goes back to the "Bottom line!" And that keeps the share-holders happy!

Actually, I just learned from Snapper themselves that the issue with the Kawi engine was they weren't able to provide an engine for Snapper that meets the new EPA standards. Too bad - its a strong engine.