On one hand our world has Cyclopses, they're just very rare. It'd be wrong to call them monsters whether they were born that way or they lost an eye to an accident or bar fight or whatever.

On the other hand in a world with monster girls, calling them "not monsters" means calling them human, and biologically distinct creatures with their own culture and history would probably find that incredibly offensive. Calling them "just less abled people" would probably offend them, especially if they had hypnosis or eye lasers or superhuman vision. And they might hate it even more if we meant "you're human" or "you're basically human" or "you're human where it counts" to be a compliment. It'd be like a Japanese woman telling her african black boyfriend "you're so polite and well-behaved! You're not Black, you're Japanese where it counts!" and expecting him to take that as a compliment.