Why the universe appears mathematical should be no surprise.

Suppose the universe is a computer U (which could include quantum-, bio-, and/or hyper-computational capabilities). A scientist attempts to reverse engineer some part P of the universe. What is produced by the scientist is a separate computer C that models the observations—inputs/outputs—of P. But C is not P. P could consist of a different (unknown) architecture/programming than what C is made of. (Also, another scientist may produce a computer D that works as well as C in modeling the i/o of P.) But since C and U—of which P is a part—are both computers, that the universe appears mathematical comes as no surprise.