Frank,
Firstly, let me applaud you for making yourself know ... not everyone does.
Secondly, the problem with your argument ... which you hear quite often from the VFRs ( even the one in the Maroochy altercation, from memory, ... "I saw him, there was no conflict"
Problem is ... do you know the IFR's next move?
He could be just about to hit a turning point or, as someone suggested, commence descent ... or climb.... or hold ... or any one of a hundred manouvers. If he knows your exact whereabouts, and intentions, he can adjust or manouver accordingly.
Perhaps, in your particular situation, the Controller thought it more prudent to give real-time radar updates to the IFR ... maybe due to the urgency of the developing situation ... rather than have you and the IFR enter into a prolonged discussion.
Every situation is different.