I think one thing worth mentioning is that any hole to the outside of your home is a huge deal from a maintence perspective. Animals try to get in through the exhaust holes, the 'flashing' around them goes bad and lets in air, they clog up with dust and dirt, the louver spring holding them closed ages out and lets cold air in, animals nest in there if the louver or grill breaks or rusts, etc. Oh and if we consider things like air fryers, toaster overs, etc then you potentially have a fire situation with whatever dust or food crumbs that may get stuck in there, a bit like a dryer fire because of lint.

I think no one wants a new hole in their home unless they can't avoid it. Its a hard sell all around I'm afraid. Not to mention the DIY spirit around electric appliances. They are such wonderful marvels because we can just buy them and plug them in! We don't need a credentialed professional running tubing or cutting through our walls to install them. A competitor asking for an exhaust port will simply get eaten up by the one not asking for it.