The CF board is basically a bunch of rookies talking amongst themselves, with little fundamental knowledge in physiology between them.
Curious, was your post just to point out their lack of physiology understanding, or did you want to actually start a thread to discuss it? I think Donald pretty much summed it up...the systemic adaptation (cardiovascular, mainly) is the only thing that would transfer much.
When I had trochanteric bursitis, I was able to maintain some semblance of my running fitness with aqua jogging. We also prepped my wife for her sprint triathlon (5k run) with solely aqua jogging. However, gaining running fitness through rowing is unlikely to happen except in the very detrained.