This reminds me of a part of Zombie Sequence, specifically the Giant Lookup Table. Yes, you can approximate consequentialism by a sufficiently complex set of deontological rules, but the question is: Where did those rules come from? What process generated them?

If we somehow wouldn't have any consequentialist intuitions, what is that probability that we would invent a "don't murder" deontological rule, instead of all the possible alternatives? Actually, why would we even feel a need for having any rules?

Deontological rules seem analogical to a lookup table. They are precomputed answers to ethical questions. Yes, they may be correct. Yes, using them is probably much faster than trying to compute them from scratch. But the reason why we have these deontological rules instead of some other deontological rules is partly consequentialism and partly historical accidents.