I can give you one good reason: they're unstable. Nightly crashes quite a lot on my phone, but Stable (and even Beta) are rock-solid. (Also, and this is just my

I can give you one good reason: they're unstable. Nightly crashes quite a lot on my phone, but Stable (and even Beta) are rock-solid. (Also, and this is just my opinion, the Stable interface is better than the Nightly interface. When it works, Nightly's a lot faster though.)