Drivers are a product. Intel writes drivers themselves and is responsible for quality of their driver to their consumers (non-corporate open source developers don't have that responsibility - they are just scratching their own itch - you like my software - great! you don't - too bad!). How can you claim responsibility for something you have no control over? If I were businness manager at Intel I would do it separately as well - I wouldn't want to be held responsible by my superriors for mistakes of other people not under me. I bet that is one of the reasons Intel does it themselves instead of relying on existing open source framework that from their perspective has a life on its own.