As I've mentioned before, 1/month seem to be clustered in certain areas. Quite likely some reps pitch it, others don't. (I have a lot of RN restaurants near where I live, and at least a third of them seem to 1/month. I also have a lot of RN restaurants reasonably near where I work, which is quite a ways from where I live, and I haven't found a 1/month near work for a long time.)
But before you lament: I think a lot of restaurants go to 1/month only because they're counter-pitched that (and other limitations, such as excluding busiest days of the week) when they ask to drop out completely, as means of keeping them in, but not making them liable for that much money to RN.
So it could be that if they hadn't switched, they would have completely left. Would that really have been better?
Keep in mind also that 1/month is just 1/month per program. I don't know what programs you belong to beyond AA (which has a dining program) and SPG (which doesn't), but in my case I collect miles with AA, UA, DL, and AS and use all those dining programs. (I also collect credits with WN but don't use their dining program. US also has a program but I don't collect miles with them.) I also collect hotel points with Priority Club and belong to their dining program (though due to few bonuses rarely use it), and I also collect hotel points with Hilton HHonors, but I haven't joined their (relatively new) dining program. So I could dine at a 1/month restaurant five times a month, crediting alternately to AA, UA, DL, AS, and PC, to earn miles or points at that one restaurant five times a month.
Also keep in mind that it's also 1/month per account. So if you have a Signficant Other who collects points or miles, you can link one of your cards to their account and earn (into their account) on an extra visit that way. (RN doesn't check whether a card you register belongs to you or not. So you can register your card in your SO's account.)