this is really against what most restaurants should try to do. I'd rather have a place make 10 dishes very high quality than 50 ok dishes. With a large menu its very hard to provide quality and consistency.
Beyond that.... as a former back of the house restaurant employee (10+ years, Cordon Bleu, blah blah) I can tell you that the only time fewer dishes is a guarantee of higher quality is when the staff isn't skilled.
http://www.huffingtonpost.com/2012/04/30/worlds-50-best-rest...