The developers of every sim use programming tricks to get a desired result. These tricks are acceptable to some people and are not acceptable to others.
I don't mind the trees in COD but I really don't like the ones in ROF. ROF is a really good sim, I own it and fly it and have brought a lot of add on planes. But I do not like the way the trees turn around to look at you as you fly past.
I guess they use this trick to keep acceptable frame rate but for me this is an imersion killer and one of the reasons I don't fly down low in ROF.
Cheers!
PS I'm not trying to bash ROF (like I said I enjoy flying the sim) just highlight that no sim is perfect and that people have different opinions on what is acceptable.