I am not here to defend bunny hopping. I think it's just as ridiculous as the next fanatic. However, I do do it in times of need. The only problem with RL military techniques that Tiffy described is that it's suicide in INF, generally. The problem is that in INF maps, I generally spot an enemy at longer ranges (ie. not covering half your screen) by "hm, that graphic doesn't belong there in this map." Someone prone on the deck is, for me, a sitting duck. I guess you could point towards the maps not having enough soft cover, or something, but I just don't think RL can carry over with our current maps (yes, there are SOME exceptions).
Come to think of it, this isn't really an argument, but rather more of a justification for why -I- do it. Many city maps (read: maps with concrete beneath your feet) generally won't give you any mercy with the "drop to the deck" technique, especially since INF engagements tend to happen on the same plane. Thus, I tend to bound around towards the nearest cover, praying that people don't hit me.
Also, I thought Rogue Spear (I'm unsure of other R6 games) had a pretty decent system of climbing/big steps.