Yes but if someone replaces the picture on the trump article with goatse, and non power users get this version for 30 minutes until the cache clears - they are going to be pretty pissed and start yelling to power users & just generally cause a PR disaster.
Additionally if vandals know their vandalism will stay for 30 min, they are much more likely to do it, which is a vicious cycle
Aren't articles like Trump write protected? If you want to edit, you shouldn't be able to, unless you have an account that's not brand new. You will be banned very quickly as soon as you start putting goatse on most visited pages.
Also, the white house PR team is actively watching and editing political figures articles. They will sort it out too.
Additionally if vandals know their vandalism will stay for 30 min, they are much more likely to do it, which is a vicious cycle