I think the non-CIO people aren't saying sleep deprivation is good or what you should do, but that there are other ways to get your kid to sleep through the night without CIO. Healthy sleep habits are important, but there is more than one way to instill them.
I have 3 kids (which I state since apparently more than 1 is a requirement for sleep knowledge

) and all 3 have been totally different with regards to sleep. First was terrible, truly terrible, but knowing what I do now, with my youngest having reflux, I think she had "silent reflux", which would explain a ton. Anyway, she was a terrible sleeper, up many times a night, etc. I got the "No Cry Sleep Solution" book, only after reading Ferber, and other books, trying their methods unsuccessfully, and found the No Cry method to be the one I liked the most. We implemented that and she was sleeping through the night. It took some work, but for the most part there was no crying. And more importantly, no vomiting from crying so hard like with CIO. She went from terrible, constantly waking up, to sleeping incredibly soundly for 12 hours straight with that method. Oh, she was way past 6 months, but we initially started with other methods at a younger age, they just didn't work.
With my 2nd, he was just an awesome sleeper from the start so nothing really needed. But, when we would go on vacation or otherwise sleep out of our home, he would get off-track and when we returned he'd often cry at bedtime for a day or 2, then back to his normal self. So we basically did CIO with him, but different kid, different personality, different response. He never cried more than 7 minutes.
Right around his 1st birthday he had a bigger setback after being in Europe for 3 weeks and sleeping in pack n' plays, with me, in the stroller, etc. This time though he was a harder sell. So when the crying went on over 7 minutes, I realized I wanted to change the approach. So with him, I would go to him everytime he woke up, I would hug him, lay him back down, and sit next to his crib. Never talked to him nor picked him up, but I was there, and he knew it, and eventually he'd fall asleep. My interventions got shorter and less frequent as he started sleeping better like he had been.
And my 3rd, she has been the best of the crew in some respects. She has severe reflux so her first 2 months were marked with incessant crying, frequent feedings, and inability to lay flat in her bed at night (which is why I think my 1st had this as well, same symptoms). Anyway, we didn't know she had reflux, just thought it was regular baby spit-up (albeit a ton of it, and with force...). Once the ped figured this out and we got her on the right medication and dose (which took some tweaking), she went from not being able to lay in her bed at all to sleeping a 4 hour chunk at night, which grew quickly to 6 hours, then 9, then 10, then 11.5 hours. No CIO (thank gosh as I would have felt terrible once we learned of the reflux!), all on her own so I can't take credit.
But she got a bad cold 3 weeks ago and has been waking up at least once overnight since then. Because she was sick there was no way I would think of CIO (and with her reflux I actually wouldn't anyway), but I've been working on getting her back on schedule and we're down to sleeping 9 hours, feeding, then another 3 hours, so she's getting there. I've just been repeating the bedtime routine when she wakes overnight, not feeding her, and she goes back down without complaint.
Anyway, my point was just that I don't any of the non-CIO fans are saying to just deal with it and suffer and crash your car cause you fall asleep on the road. Just offering alternative solutions to the waking problem.