I agree with you. I definitely depends on the speakers and their pattern of dispersion. I had a running battle with georgehifi when he was still on this site. He said that it was a no-no under any circumstances to have the rack between the speakers, and I said that in my particular case, I was using horn speakers whose dispersion pattern could not even interact with the rack that is between them.
I think that in some cases it is a problem, although I never noticed a problem even with ordinary direct radiating speakers, but I think that the reason that some people imagine it to be a problem is because they think that the gear is getting in the way of the sound waves that are creating the "image" when in fact the image is not being created where the physical rack is, but at your ears, even though you perceive it to be at the rack location.
My belief is that individuals should try it before they just believe out of hand that it won't work for them.