Haha... A little bit of column A and a little bit of column B.

SO many things effect is we get acne. Yes one of them is hygiene, another is diet, but no, there isn't a disease or condition that specifically prevents acne, it's just your body/skin.

Sometimes not washing your face is a good thing.. i.e. Maintains the acid mantle, limited (significant) irritation, etc. Also, you may have not so favourable elements, but offset them with others (e.g. diet high in omega 3's, good exercise/active lifestyle, good hydration, low intrinsic hormonal fluctuations/high threshold). Genetics is a good way to sum it up, but there's more to it.

As I said, acne/health is multifactorial. No body "should" have acne, just some of us don't, some of us know what our bodies need to successful combat it, some have no idea or couldn't be bothered, and some are just unlucky because nothing is in their favour.

In saying that, don't look a gift horse in the mouth. Your body is constantly changing from the day you are born to the time you leave this life. Have you ever heard someone say "I use to be able to eat anything I like and now I eat a chocolate bar and my arse explodes" or something to that effect... If you know you should be doing something better then couldn't it be considered somewhat ignorant toward the general state of your health? Just remember, drinking 5 cans of soda a day is leading you down the track for type 2 diabetes mellitus, chronic heart disease, atherosclerosis, retinopathy, neuropathy, etc, etc, etc. It might not effect you for 20 or 30 years but, like smoking, once the damage is done, it's too late.