I could not disagree more.
A much better word than 'fun' is 'immersion'. VR puts you IN the car, ON the track, AT the race venue. You have to experience it yourself but the sense of presence is incredible. I know there are a multitude of personal, technical and financial reasons why VR isn't for everyone but for me it's an absolute perfect fit for sim racing. Full 360 degree freedom with a view that changes with your head movement is brilliant, but the biggest bonus of VR is the stereoscopic vision that works just like our eyes do to present things in proper 3D. Everything you see occupies 3D space and has a solidity that the best 2D screen in the world will never be able to reproduce. Opponents look and feel menacing alongside you, and they have a virtual mass that makes you more wary of collisions. Cockpits come alive in VR, apexes are easier to judge, the sensation of speed is unrivalled, and the scale of the environment can be overwhelming. I think it's pretty bloody amazing. Races are thrilling, feel dangerous, and the first few times you crash in VR you WILL brace for impact. Couple VR with a motion rig and the immersion simply goes of the scale.
I've went back to 2D when my Rift was out for repair (a 50" 4k panel right in front of my wheel, so a pretty good setup) and I found it terribly dull and insipid after VR. I was back to playing a videogame on a letterbox screen rather than feeling like I was actually racing cars on a track. It made me question how I ever got into sim racing in the first place. It just felt boring, and detached, and uninvolving. And all this is with a Rift CV1 with its narrow FoV and low resolution. I plan to upgrade hardware next year to something with a higher res and wider FoV, and man... I cannot wait.
2D racing on triples or a curved superwide has its place but comparing it to VR is futile. They are two totally different beasts with common components that achieve a similar thing in totally different ways with completely different results.
VR sim racing a 'gimmick'? No. No it's not. It's actually how it's meant to be played. This is meant to be a simulation, after all. And surely simulation starts with how we perceive things. That's not a 2D panel with your bedroom visible around the edges.
In my humble opinion, of course...