The article says that you can send it in to be recycled. Idk, but if you get a voucher for sending it in to use for buying the next one (or another product) people might actually do it and it is not as bad as throwing it away. A rechargable battery would also degrade over time and since it can only be a tiny one... Also there is a chance people might use it to tinker.

However, I agree that this design choice (resulting in the low price) is very questionable to say the least.