Anyone new to Lisp will quickly find that among certain folks there is very much an “us versus them” mentality when it comes to Scheme and Common Lisp.
Is it just human nature that drives the mentality? Is it boredom?
Since Scheme and Common Lisp are both Lisp dialects, in some ways they are very similar; but in other ways they are quite different. The thing is that every language decision is a trade off from which we can learn. Most students of programming would look to both the similarities and differences in each language and recognize their function and beauty!
One thing that I can guarantee that you will notice pretty quickly once you start hanging around Lispers (in general) is that there is a noticeable difference in attitude and demeanor among folks that have studied and appreciate both Common Lisp and Scheme, and the folks that have not.
The folks that have studied and appreciate both languages are simply a much more pleasant group of people to be around. Perhaps that is how the expression about “the haves and the have nots” came to be?