TLDR: Developers should be able to set limits (filesize, image resolution) per filetype.

The reasoning: We have a lot of customers that just drag and drop raw 40 MB JPG's straight from their digital camera or save photos as PNG files. When those files need to be processed by ImageProcessor this causes extremely high memory usage. Images on a website typically never need to be more than 1 MB in size or have a resolution higher than HD. But you don't want to put this limit on all file types. Files that are downloaded like PDF or video files should have a higher size limit.