I believe I'm not understanding what you mean. My issue is not that they show in front end to the customer, my issue is that they don't show up here:
Some of my products differ only by tiny details (I can imagine it's not me in this siuation) and if a merchant's employee is not very familiar with differences in the products and can't enlarge this during order preparation this could lead to troubles.
I'm in the same boat as you that the original images should not be visible in FO or by bots or scrapers, but they should be visible in BO (or at least let's make BO use some of the larger thumbnails with watermark) and keep the originals for regeneration only.