It's not ASIC resistant at all. You could make an ASIC for LTC if you seriously wanted to and though it was worthwhile. What you mean to say, more precisely, is that Bitcoin specific ASIC's (SHA-256) will not work for LTC.
It's ASIC resistant. You can build ASICs for it, but scrypt is designed to make it impossible to get a worthwhile efficiency gain from doing so compared to general-purpose hardware.