I think it's because most tiling WMs have a really steep learning curve, often not even providing basic things like window title bars or automatic lock/suspend,

I think it's because most tiling WMs have a really steep learning curve, often not even providing basic things like window title bars or automatic lock/suspend, expecting the users to configure all that to their liking. Perhaps some sort of a gateway drug is needed, something can help introduce people to tiling while also providing good defaults and the usual desktop environment comforts (title bars with buttons, lock/suspend, volume and networking controls, a proper settings app, etc).