Well, there's a few points I can make:
1. It's Alabama. In the future when most people don't even believe any of this magic man in the sky stuff as we learn more and more about everything, Alabama will still be 99% Christian.
2. Church, for any atheist or non-believer, is worse than jail. I'm sure people will take the 30 days in jail or whatever, and pass on going to church for a year, I know I would.
3. As for it being unconstitutional, it doesn't really matter. The US constitution and Bill of Rights is just a joke. These things are being broken all the time now. Cops can enter your home without permits, they can just come in anytime they want now. The "US Constitution" has been broken a few times already.
4. On separation between church and state, it has never been so. Politicians push their God belief to get elected. An atheist cannot even realistically run for high office, much less win, so the whole church and state separation was long gone a long time ago.
Honestly, at this point, all these laws and rules and constitution and church and state separation and all this, it's all just a big joke. None of it is real, these things get broken all the time. It's like American rights, we don't have rights, we have privileges that the American government gives us, and that they can take away anytime they see fit.
So, if Alabama wants to let people go to church for a year to serve their sentence (lol) then I don't really care. Someday people will either wise up and get smart and realize none of this magical man in the sky stuff is real and that we need to focus on real things, or people won't, and we'll continue down this path of running this country and running our laws based on fantasy and fiction.
Either way, I'll be dead in 50 years probably so, yeah, I'm sort of done justifying/arguing about what goes on in this country (or any country), it's all just silly and I'm just going to sit back and watch, as everytime a step moves forward, we move backwards, like this.
That is all.