I think they are doing just that. If there is a market for fuel injection, and a sustaining profit can be made, I am convinced they will do it.
But just look at OS. Some aerobatic crowd people use the engine, and pay through the nose for it, to be beaten by the humble MVVS glow engine in matters like reliability and userfriendliness. OS is a huge company that can afford to have up front devellopment, even if they loose bigtime on it. The spinoff is advertising value.
Judging by the teething problems, fuel injection has to come a long way before it is ready for our engines.