It's a good glue language, like Python. Better than Python in the sense that its internal representation is based on tagged values instead of ubiquitous pointers: for example, 43243 represents itself and isn't a pointer to a some reference-counted PyObject representing an int.

And because Emacs Lisp a lisp, you get extensive syntactic malleability that you can use to build DSLs and convenience facilities.

Elisp is actually a very nice little language.