The inertia of current large enterprises using Oracle sure, if the cost to move from Oracle is very large then they'll accept the risk if they even consider it.

Not so sure that applies to new customers though, they won't hemorrhage customers but they could see a slow gradual decline as the odd large enterprise folds, moves to something else etc.

I think if Microsoft continues down the path it appears to have really committed to the potential for .NET (Core) to go toe to toe on Java on none-microsoft platforms is there.

I certainly think that is the intention (along with making Azure a more attractive platform).