It's being presented as testing hardware, so you can get to know their stack. At $19, it's
probably being subsidized substantially.
In the same way free AWS instances are not adequate for hosting a production website, this is a toy for devs to get to know their stack...
The real question for this device is, is it hackable, i.e. can you change the software running on it, or open it up and solder different hardware to spare pins?
It looks like people have done this, but it's surprising amazon would sell a devboard without catering to it:
https://github.com/dekuNukem/Amazon_Dash_Button