Anyone Else Feel Guilty About Changing a Sim's Genetics?

I usually don't change their looks other than hairstyle. I've been playing rotational play lately and I ended up wit two sims in different families that had enormous ears. So when they grew up I had them get married. I am anxious to see what their kids will look like lol. I think that all of those different oddities may the game more fun for me. I wouldn't feel guilty about changing things like body or face features...I would look at it like plastic surgery.