Maybe price? Look at the way cheap system wheels and carbon frames have taken over the market. Groupsets still cost loads. Economy of scale for large manufacturters using their own groupsets
[quote="Seanieh_The PengeAvenger©"][quote="Elliot M"]
Obviously there's SRAM, but there is a rumour another well known component manufacturer will come out with a groupset next year. I don't know who. My money would be on Specialized or perhaps Trek/Bontrager though.