There are lots of restaurants that, if you try to make a solo reservation, it will show no availability. I can't remember which ones, because I stopped trying years ago. Now I, too, make all my ADRs for two people. Who knows? Maybe I'll run into someone I'd like to invite to share lunch with me, or maybe DH will suddenly surprise me and show up. Neither has actually happened, and when I get to the restaurant, I just say that DH had to go back home, or my dining partner's sick, or "No, I'm the only one here" without explanation. It's never been a problem, and I've never been charged a "no show" because one of the two people didn't show up. Besides, it's the same size table whether it's one or two people.