Scaling an image doesnt change image linked to from existing post

Thank you for a great system. I use both www.remarpro.com and WordPress.com on a weekly basis for several sites.

When I create a new post, upload an image to it and insert a thumbnail to the image in the post, which links to the media itself – and then later go to Media and scales the image down, then the post isn’t updated – it is still linking to the original image. The downscaled image it postfixed with some random characters, like this: image.jpg -> image-e1369252531325.jpg

I don’t know if that is by design, if there is any situation where this is desired – but in the above situation, my guess would be that most people would like the image to be resized, also on the existing post?

It’s great to have the posibility to recreate the original image, but why not make a backup of the original image instead of making a new image with the new size? (I hope you understand what I mean with this).

What is both WordPress’ and the users’ comment on this?

Best Regards
Svend Koustrup