Seems to me that the whole point of destroying 'idols' was to stop people from continuing to worship them.
When the Jews entered the Promised Land, it was full of practicing pantheists, whose temples contained images or standing stones representing local deities. These people were NOT going to hear of a universal invisible spirit, they were not going to turn against their faith(s), so the Israelites destroyed the religions. And the cultures and the people.
My understanding is limited, so PLEASE correct me, but I believe that is the same reason for Muhammad's actions...to make it impossible for the conquered idolaters to continue their practices; to MAKE them turn to and depend upon Allah.
Not arguing that there are nicer ways to spread a religious faith, just sharing my viewpoint of WHY images and temples/sacred sites were destroyed in ancient times.
Buddha figures in a museum were not being worshipped or believed to be avatars of the Buddha, and neither were the Buddhas of Bamiya. The destruction was pointless and completely against the principles for which Aaron's and Muhammad's orders were carried out.
Therefore the actions were against the PRINCIPLE of Muhammad's teaching. I am not aware of any approval of 'Destruction for destruction's sake' in Islamic teaching, correct me if I am wrong.
Sylkat