Aside from mechanical issues, shifting gears when you don't expect it is about one of the worst experiences you can have on a bike. Being in a lower gear than you expect and spinning out or being in a higher gear and having no traction is terrible. The Nexus is super easy to shift (and can shift when you are stopped) has a bigger gear range, and is predictable.

Also, when bikes were launched, these didn't exist. Now it's likely you can get an all around easier ebike for about the cost of one of these so it's a no-brainer.

> Your argument seems to be "advanced users don't want this"

No. My argument is nobody wants this you might think automatic shifting on a bike is a good idea, but every time it's been done people hate it. It doesn't work like an automatic in a car.

The fact that it's far more difficult to change a tire means users are even less likely to learn basic maintenance. It's nice to say "They'll take it to the shop!", but that doesn't help when they are on the bike trail 4 miles from their car. With a somewhat normal drive-train another rider can give them an assist. With this, it's unlikely anyone has the tools with them to help out.