Also consider that with several contributors commenting on the same post it gets boring scrolling down each one through the same information Roger
in business-communication top posting and TOFU is normally because with TOFU you need only the last mail of a conversation and with the top-posting you need not to scroll and see the whole answer in the preview after select a message
so this is all a point of view
But business email is not normally archived for later use. It is essentially one time communications with a few exceptions. And this difference is essential between a mailing list and simple email exchanges. Just my 2 cents worth, and that ain't much these days
where do you work that you are allowed to delete business-communication? :-)