Wait, wait, wait, wait. So they're selling a product...to make money?!?! Say it ain't so!
Naw, but putting me being an ass aside for the moment, seriously, they have a demographic they're selling to and they created the 2ds specifically for that demographic. They're making it cheap, they're making it kid/casual safe, and they're making it kid/casual-friendly. I can see why it might be hard to understand how it's less likely to break if you don't have small children or teens, but trust me. It's must less likely to break this way. It's a no-brainer for parents.
Look, it makes perfect business sense and it makes perfect practical sense. You shouldn't be upset they made a new product aimed at a different demographic. Just think of it as adding a lot of people to the nintendo and 3ds consumer base.
Also, it plays DS games too, so you're incorrect about that as well.