Why would you need to introduce your co-workers to Emacs? I have recently got in touch with clojure and developed in atom with parinfer.
Was I missing out on something or is the difference between clojure and common lisp decisive?
The main reason is that the emacs mode for common lisp is mature and is what almost all CLers use (unless they use a proprietary environment). So, its CL-specific features are generally more polished than other editing environments (e.g. it has a macro stepper, various cross-reference utilities and other such niceties which are either lacking or buggy in other swank clients).