Speaking for myself, I am a pretty big animal lover all around. I love cats specifically because they are interesting and beautiful.
I don't find it to be a loneliness issue. Until last summer, I had a cat for 16+ years. I got her when I was married and I kept her when we broke up and I loved the cat in all situations. My sister and her husband have 4 cats and I love all of them.
Certainly though, if someone was lonely, a cat or dog could be a great idea. I can't think of anything more natural than someone who is lonely wanting company. Pets provide unconditional love and good company. I would highly recommend a cat or dog for someone who is lonely.