I've always seen the value in vendor-neutrality and why I chose to be a Java developer in the first place.
Me too. But in reality I'm locked-in with such vendors as Oracle and IBM, that locking myself in with SpringSource is irrevelant.
If you are trying to suggest open source is an alternative to standards, that's completely a false choice.
No. I'm trying to suggest that open source is an alternative to vendor lock-in. Or rather an escape from it.
The goal of open source is transparency, not vendor neutrality.
I love that word - transparency - really. I miss it in each public tender I'm indirectly involved in...
Basically, your only option is forking a large code base, which has seldom worked in practice in open source history.
And I must directly disagree with you. You work for Oracle, so you should remember what happened to Hudson/Jenkins and OpenOffice/LibreOffice. I'm not saying that'd worked just as well with MySQL/MariaDB however...
In my experience, most IT decision makers do indeed care about vendor neutrality at the API level and embrace it whenever they can, especially in the Java world.
In my experience (Poland) most IT decision makers follow the simple, universal rule - you won't get fired/blamed for choosing IBM/Oracle/Microsoft. If I were a (real) decision maker, I'd opt for true open source and standards. And you know what? I believe that going full open source (not necessarily FREE SOURCE - the key, as you've mentioned - is transparency) would make sticking to JavaEE APIs easier. But now I just don't believe what my application server provides (I know, I'm boring)