In other words he did something because he thought it was okay to do it, he did it because he didn't like the way it was done, but he did not consider that in this case there might have been a reason why it was done the way it was and not the way he wanted it.
There were many things he could have changed, and improved things, but since he didn't bother finding out why things were they way they were changing things for the better was at best a random outcome.
I've seen so many people jump into a business, want to prove themselves, and start changing things without understanding the context in which that thing was built. (Similarly, though less often, businesses expanding into new products or markets.) "Tell me what will change if you stop doing X" is thus added to "Tell me what will change if you start doing Y".
To be fair, citing Chesterton's Fence just make me sound wise (and/or a little curmudgeonly); the better story for the point I'm making is the hospital bed where someone dies every Thursday morning at 10am ... only for video footage to reveal the cleaner unplugging machinery to plug in their vacuum cleaner every week.