As their website copy suggests, it's for people who just deeply love the medium of videogames. Not people trying to be frugal with their entertainment purchases or have a mainstream handheld console with a deep library of AAA titles. It's not supposed to be an amazing emulator for retro games. It very transparently just trying to be a fun little device that inspires joy. Twelve games delivered over the course of time, all surprises. Just some fun experiences for the people that just love *games*.
I dunno why people are comparing it to stuff like the Ouya. The Ouya and similar devices were always trying to supplement if not outright replace a traditional home console, on the basis of having a ton of games, and aggressively priced games at that. The Play Date is just a tiny experiential device that is trying to do one very specific thing.
Also, for people balking at the price, check out the OP-1, OP-Z, and Pocket Operators from Teenage Engineering. All limited production synths, clocking in at $1,300, $600 and $50-80 respectively. If anything, you should be grateful that Panic isn't marking this up to like $250, which they could absolutely get away with and still sell out.
See, the thing about that is that this is a device that will only ever have 12 games (barring anything the community creates for it). It's not a $399 home console from Sony/Nintendo/Microsoft that you're going to be playing every release on for the next six years. You're never going to be forced to deal with dumb implementations of the crank shoehorned into AAA first party titles that would otherwise be better without it. It's an integral part of the device that some experiences will be wholly designed for, and not traditional videogames. This isn't some "you have to swing a wiimote around for 60 hours of Zelda even though a button press would do" shit.