That's often true within dynamically typed languages, but statically typed languages definitely don't feel Lispy. Moreover, messing with static type systems involves much more maths than hacking.
It is perfectly possible to write/use a lisp that is statically typed and still feels like a lisp. AFAIK the closest thing to this currently is shen http://www.shenlanguage.org/.
None of the things that make a lisp a lisp prevent static typing. Some common constructs could be hard to figure out the types for, but they figured out the types of transducers so I doubt it is impossible.
