The angle I'm coming from is the cost factor, simple truth is fixed wing is just too expensive to operate vs what regular income you can generate at the low end. As long as your 300hp Cirrus engine costs $50k USD for 1950s tech, while similar modern marine engines are 1/3rd that and car engines 1/10th it will never make commercial sense. Aviation will always be stifled by the ridiculous cost of compliance and litigation. Most of what I read says the FAA basically makes it close to impossible to get the SE piston IFR 135 anyway (more cost), and you will always be haunted by the fact that they could change their minds and shut it down if there are 1 or 2 accidents.
Face it governments just don't want mass light aviation, they want it expensive to regulate the numbers and control flow of people and goods, only made worse by the misplaced specter of security issues with aviation. They will bend over backwards for the drones to happen as this keeps those nasty aircraft out of the hands of the general public, and in the hands of large corporations.
Single or Multi engine, the only profit is had at high end contracts with corporations, otherwise you just don't get the flow of income to make it worth it.
I'd love for this to take off en-masse, I'd even get involved my self with a Saratoga or something, but I just see it consuming cash into an endless pit.