its not that I want to do a lot of customisation, or even heavily mod things, I just want a consumer desktop, with the ability to expand RAM (i know my iMac has this) HDD (i don't want external drives all over my desk) and Graphics.
I would even buy them from the apple store if they wanted to keep the margins up.
sell a base tower with room for expansion, then sell upgrades from the online apple store.
I would buy Apple approved HDD's (in a custom drive bay if it made them feel better) and updated Graphics cards, inline with the Mac Pro for example.
I do not need the 8 core power of a mac pro, I just need more hdd space and a better graphics card.
The Mac Tower would be perfect for this, and Apple could continue to keep me onboard and sell me their hardware for my upgrades.
There is a Market, it could work, and I truly feel Apple are missing out