General Aviation pilot reported taking evasive action during cruise in response to a near mid-air collision with another aircraft that had departed from a nearby airport on an IFR clearance.

Narrative

At XA:36 local time; I departed ZZZ for ZZZ1 in Aircraft X. It was a flight I have done many times. The majority of these flights are performed VFR without flight following. In order to stay under the Class B airspace but above the pattern altitudes of transitioning airports (UZA); I fly at 3000 ft. MSL (2000-2500 AGL). I monitor the CTAF for UZA and make calls that I am transitioning above the airport at 3000 ft. This morning; shortly after tuning into UZA's CTAF; I heard one plane departing the pattern. I made a call at 10 miles from the east. Before my 5 mile call; Aircraft Y on the ground at UZA Aircraft Y announced he was departing Runway 2 with no announcement of direction of flight. I responded that I was 5 miles to the east transitioning at 3000 ft. over the field. I received no response. His next call was to the effect of 'making a right turn to 150 up to 3000 ft.; last call'. I made a response to the effect of 'I am east of the field at 3000 heading west' but he must not have heard it due to switching to CLT Departure. I glanced at on-board traffic and noticed a target 600 ft. below me and climbing in my direction. I looked outside and by the time I saw the plane; he was headed at me at my same altitude and banking to head west bound. I made an evasive maneuver to the north. By the time he rolled out; we were both on a west heading at 3000 ft. less than a quarter of a mile from each other. I immediately tuned into the first CLT Approach frequency I could recall (120.05) and announced that I was Aircraft X over UZA and a plane had been directed to turn right at me. The Controller said 'it would be nice if you could descend a little bit; he's IFR'. 1) even though he failed to announce pertinent information such as direction of departure; the pilot in Aircraft Y departing UZA made calls on CTAF but he was obviously not listening to anyone else. On a perfectly VMC day; he chose to get his IFR clearance on the ground and ignore CTAF protocol. Yes; he has an obligation to follow IFR clearance but certainly not to his own (and my) detriment2) the Controller decided to give the pilot an initial clearance to a southeast heading even though the plane's destination was a northwest heading. This is not to mention that the southeast headed caused the pilot to make a right-turn departure in a left-turn pattern. This Controller failed to see me coming from the east even though I had been on a constant heading and altitude for nearly 10 minutes. Then; he tried to infer that the traffic conflict was my fault and I should have been lower. Had I been lower on this flight; I would have been in conflict with the traffic sooner and would have had less time to react to the plane making a 1000+ fpm climb directly at me. Furthermore; I would have been closer to the traffic pattern at a 'busy airport' as he told me UZA was. 3) I had every right to be cruising in the manner I was. Per 91.159; since I was under 3000 ft. above the surface; I was allowed to cruise at 3000 ft. Again; I would not want to cruise lower due to UZA's busy airspace and I can't cruise higher because of the Class B and wake turbulence from planes inbound/outbound from CLT. I could have been on flight following but I felt it was a safer measure to listen/call on UZA's CTAF.