Maybe I don't understand the concept of "developer mindshare" well enough but it seems to me that Oracle does engage with the user community and not just the business community.

They do this through user conferences such as Collaborate and ODTUG (which is developer specific) - those conferences are much more technical in nature than the marketing oriented OpenWorld.

Oracle also have the OTN and its ACE program for engaging with the technology people, including forums, beta programs, code sharing site, etc.

And of course, Oracle supports the local user groups which are also technology oriented - many of those user groups are highly critical of many Oracle decisions (and you should have heard the noise when Oracle Support site switched to flash) - but Oracle still supports them because they know that an active user community is essential.