A good auto-shifting bike could be beneficial. It might well help encourage more people to ride. A market exists for such a thing. That's why there continues to be so much R&D into creating a viable design.
The Land Rider (and the Autobike) aren't it, of course. The obvious problem is a shifting system that doesn't account for individual differences in riders, and that therefore makes even approximate optimization of shifting a matter of chance. And it's still entirely possible to get "stuck" in too high a gear going uphill with one of these, and that's a newbie's most common shifting error with any type of shifting.
An even bigger problem is that these are heavy bikes that are unlikely to fit or be comfortable for most riders. When adults quit riding they do so because they find it unpleasant. It hurts, it chafes, they get saddle sores, they get knee pain, they get back pain. Most of these problems stem from buying mass-produced bikes at discount stores, and the bikes are the wrong size, not fit properly, have big fat soft saddles, and are poorly assembled.
These informercial bikes are just discount store bikes with a gimmick so they can double the price. They will not make riding any more comfortable for most buyers.
The focus on shifting as complex and maintenance-intensive is a classic "straw man" advertising strategy. It's easy to point to and talk about, and the gizmo is easy to point to and identify as a solution. The fact that shifting is not really a big problem, and not the thing that prevents most attempts to enjoy cycling, is not a message anyone is paying big advertising dollars to get aired, so it doesn't.
RichC