Owners change their enclosures, either entirely or partly, in correspondence to the needs of the snake, or even their own. Just because your enclosure can support all of the requirements of your bp, does not mean it cannot be bettered.
I personally make changes when it allows for greater simplicity. I also make changes for aesthetic reasons, as long as this does not affect my bp negatively.
So are you asking why we suggest changes when you do not think they are needed? It is always up to the owner to decide what changes are necessary or required, and when members suggest changes it is not always because something is being done wrong, just differently or perhaps more complexly. I appreciate the criticism on my enclosure as it can help point out where I can make improvements.