Why is the quality of the covers in the mobile apps so much lower than those in the web apps?

I use Music Connect, Movie Connect and Book Connect for my CD’s, DVD’s/Blu-rays and Books/Magazines. I always make my own high resolution cover scans and replace the ones provided by Core. My image files are usually not larger than 500 KB. In the web apps the scans look great, however in de mobile versions they are very fuzzy and of low quality. Most of the times it’s impossible to read the detailed information on the back covers, for instance. Why do you change the resolution of the images when syncing them to the mobile apps? I have plenty of space on my iPhone and/or iPad, so file space shortage is not the problem. Or at least make it a user option in the syncing process to use the full resolution or the compressed resolution from the web apps. Or is there currently a (hidden?) option to maintain the same picture resolution in the mobile apps and in the web apps when syncing between these two platforms?