Now after perusing old threads on GT Planet & Reddit covering cameras in GTS and other simcades and sims I now realize why I have less aversion to cockpit cam, even given the fact that GTS cockpit cams are woefully inadequate in that you can't remove the driver arms and there is no FOV adjustment besides the +/- 5 height/depth... It all comes down to my TV and how far away I am.
I was already familiar with optimum distance from screen depending on resolution and size. 18 months ago I moved from a 42" 1080p to a 55" 4K. I now sit closer to the TV. A few months ago I also changed my "cockpit" (don't laugh - an ironing board and a kiddie Winnie the Pooh chair) so that I am now sitting lower. That has the top of my wheel protruding into the bottom of the screen a bit.
@azrilnazli has pointed out the advantage of being close to the screen to make cockpit cams work. The thing is, with my 42" Full HD it was impossible to be very close to the screen because of pixelation and cockpit cams just made the track hard to see. It messed up my braking points, my situational awareness and my overall perception of what was happening in cockpit cams.
Now that I have a larger screen with higher resolution and am sitting closer the cockpit cam clutter is much less offensive. I even went back and messed around with the DiRTs, AC and PC2 and found that those cockpit cams are also more comfy with my current setup. I can clearly see the track despite having 35% of the screen covered with things that would not "block" my view in a real car.
I also stopped the car next to a landmark on various tracks (start of rumble strip, start of barrier, start/finish line etc...) and switched between the various GTS cams. It is quite obvious that the cockpit cam has the POV sitting further back, and that the bumper cam roughly has your eyes around the front axle and much lower in height. That is why I feel the car better with cockpit cam. Basic geometry shows you that the closer to the front of the car you are the less you will perceive oversteer. Bumper cam is fine for me in FWD and 4WD cars but in RWD cars I am much more consistent in cockpit cam because I can perceive oversteer earlier and its visual effect is greater.
Unfortunately, GTS cockpit cam leaves much to be desired due to the small amount of customizations we are able to make to the HUD, POV and seating adjustment. However I got used to it pretty quickly and it's made driving much more enjoyable and consistent for me. I really need to see a part of the car in front of me. Roof cam is way too high and feels completely unnatural. Bumper cam is too low and oversteer catches me out too often in that view.
I'm not trying to say "everyone needs to buy a 4K TV and change to cockpit". But those who do have a large high-resolution TV might want to give it a try. You never know, you might like it. I absolutely hated cockpit in GTS until I gave it a chance.