"I didn't even know I was hungry" (The Food Appreciation Thread)

Yolk and white have different chemical compositions so they'll cook slightly differently and should thus be kept discretely so you can have your different egg-bits how you want them? Alternatively, it's for a sense of perfectionism that says "if you wanted yolk in your white you should've scrambled them in the first place".

Eggs "over easy" or "sunny side down" or "over hard" are all options (which are commonly used enough in the breakfast industry to require names!) which entail cooking the yolk to some extent. "over hard" entails breaking the yolk, presumably leaving a cooked flat yolk in the middle of cooked egg white.

So yeah, it's only a crime if someone wanted to break their own yolk, or if you're trying to uphold unrealistic standards of beauty for fried eggs.