DISCUSSIONS on “Rules for online games in HoMM3 and formulas for calculating player rating.”

It’s best to ask the person who came up with the rules about the reasons. But your thoughts are definitely incorrect, as scouting what’s in the treasure without breaking through the guards gives a significant advantage. I think there’s no ban because it’s not always clear whether a passage is buggy or not.
On 8mm6a, you can run everywhere without breaking through any guards.