I would guess that part of it is to tear down what’s there so they can rebuild in their own vision. I think this is a desire that any engineer can understand- and also understand that it often has to be suppressed because it’s a common blunder.

How many engineers have walked into a legacy project and their first instinct is to rebuild? Of course this is sometimes warranted, but almost always costs way more than anyone expects and doesn’t necessarily lead to a better outcome.

Edit: I’ll also add that this mentality is more common in younger / junior folks, which fits the context here.