Except the fact that the person who invented it says it should be a GET in his documentation of how it should work.  But the intentions of the guy who defined the standard doesn't matter... 

And the argument that a JSON-RPC request has to be a POST is irrelevant because the LP request as defined by the Deepbit spec is not a JSON-RPC request just because its response looks like a JSON-RPC response.   Two different standards can have responses that look the same without being the same in all other ways.   

You've defined a new standard.  A "DiabloD3 Long Poll".  Cool.  But they people who are following the published guidelines for the "Deepbit Long Poll" are not idiots (as you appear to be implying).  They are just doing exactly what it says they should be doing.

It's a pointless argument.  Fortunately, it's easy enough for pools and proxies to support both by not caring if there is a POST body or not.