This is just one style, not representative of all Lisp web development. You can have any style you want. With continuations you can even use a procedural style where your program describes a workflow of multiple pages.
(Whether MVC is the right style is a topic for another discussion.)
Good too know. I would like to give Lisp a try, but I've only just being able to sell a php shop on migrating to python/django. Lisp is a near-impossible sell to every web dev shop I've worked in.
(Whether MVC is the right style is a topic for another discussion.)