Xbox 360 GoD format?

I've been playing with BadUpdate for the Xbox 360, and I've found that the console can not load the ISO format from the external Hdd, requiring the conversion to GoD Format (Games on Demand), requiring a tool like Iso2God. What surprised me was many of these games are really small compared to the size of the DVD they were originally burned on. Some cherry picked examples include: Bioshock (4.6Gb) The Jackbox Party Pack (1.3Gb) Popcap Collection "Pvz1" (464Mb) - minus about 16 Gb Total! I absolutely love the preservation of the original Iso files, but hosting a GoD Format of games could save a lot of bandwidth, especially when considering emulators also recognize games in GoD format. The format selector in the Wii vault is incredible, is there any reason why GoD formats are not hosted? "I like old games!"