Why is image style generation only available when authenticated

The image resize module in drupal 7 requires a logged in user to generate an image. Why is that? Consider this:

User x logs in, creates an article with a couple of images. This content type is configured to show the "large" and respectively "thumbnail" image sizes on the main page of user x's site.

This user has a pretty crowded site, so after hitting publish, his site are hit by a couple of anonymous users which will get "generate"-links since these thumbnails doesn't exist, but these will return a 403 since they aren't allowed to create images.

I don't get why anonymous users aren't allowed to generate these. The generation is already locked so races can't be an issue, further - these "generate"-links aren't open to manipulation so you can bind an unlimited amount of php workers since they only accept "valid" image paths - which then would already be created.

Also, returning the actual image when it has been generated doesn't make sense both performance and client wise. You do an unnecessary read on the server side when opening the image and passing it to the client, also - clients and/or proxies cannot cache this properly. Please see http://drupal.org/node/805416 for more information about this.