Lou continues to sign autographs because people continue to pay him for his autographs and pictures. Simple as that. No matter what we think, Lou continues to have a line at the Arnold Expo, and still draws them to him.
And if I didn't have a 'press' emblem on me, it would be much harder to just even take a picture of him.
Unfortunately, my friends don't think highly of him, just for the reason that unless they give me some money, he won't talk to them.
However, if you have ever been to a sports memoribilia expo, or any special convention expo (Comic Con, Science Fiction expo), the actors do the same thing.