You can disagree all you want, you'll still be wrong. It's not about price point, it's about truth in advertising and not misleading consumers. If a customer complains that a New 3DS Only game doesn't work on their 2DS, you point to the front of the box that the game came in that explicitly says "Only For New Nintendo 3DS". If a customer complains that their Nintendo Switch doesn't play their Nintendo Switch game, you fucked up.
The hybrid nature is right there in the name, making it - again - a truth in advertising issue. Technically, so was the 3D in 3DS, but Nintendo was able to get around that with '2DS' - a very clean and simple name that simultaneously communicates that it's mostly the same console and makes the removal of 2D clear, all by changing a single number. It's a perfect solution. If you can think of an equally perfect equivalent for a non-switching Switch, go right ahead. I'll wait.
And guess what, the Joy-Cons are not entirely optional. Try playing 1-2 Switch, Snipperclips, the built-in Street Fighter 2-player or several of the games in Super Mario Party without detachable Joy-Con or the tablet form factor with tabletop mode. Spoiler: you can't, which is my whole point.