Being single, middle aged, and for some unknown reason unattractive to the opposite sex :-), I eat out by myself on a regular basis. Sometimes, I'll take a book and read, but I like to watch people and see what others are eating. It's never bothered me.
One drawback is that if I'm trying a new place, I can only sample one or two things. But, if I'm impressed by the first visit, I'll go back to try new dishes. I prefer eating in the restaurant to ordering take-out.
Often, the restaurant manager or owner will come by to chat, even comping me a glass of wine.
But, I have a friend that absolutely, positively, never in a million years eat at a restaurant by herself! And my sister told me she "feels sorry for those lonely people that have to eat by themselves." She's even invited them to join her family at their table. While that's a kind thought, I would never join a table of strangers. I'm much happy dining alone.
What's your position on the subject?