Competition
What customers want out of OpenStack is the ability to switch vendors and the competition that creates. If they didn't care about avoiding vendor lock-in, then they would just go with one of the proprietary vendors and prepare for a wallet-ectomy a few years down the road once the market graduates from the "growth" to the "monetize" stage.
Canonical and Oracle have the right idea from the customer perspective. The reason that Red Hat isn't joining in is because they think they can use their name to walk away with the market. I'm not sure that will work in this market though.
