Both are common sayings and easily googleable:

Hanlon's Razor: Don't attribute to malice what can be attributed to stupidity

Chesterton's Fence (worth googling as it's a nice little parable, or it might be a derivation of the parable,can't quite remember): Can boil it down to: if you don't know what something does assume it serves a purpose until you've figured out what purpose it used to serve. In this case I'm implying these people are playing the part of wanting to change the fence without knowing it's purpose.