I am not knocking your take on this at all because I know it is a very tough issue to sort out and even experts have varying opinions (partly because --thankfully-- there just aren't enough crashes to have a large body of data). I completely respect your opinion, and you may well be right that it is safer. However, I want to present the other side, which is where my opinion lies. I base it largely on talking to my brother in law. He designs air bags for commercial aircraft and is by pretty much any measure an aviation safety expert. He has testified at safety hearing in both the US and England (and likely other places i just don't pay that much attention to his career

) and is very often quoted in articles that come out after an airlines does go down. He did not use a carseat for his son on airplanes and thinks they are more dangerous. The short version of why is that the vast majority of crashes either kill everyone on impact or no one. A car seat does you no good in the first scenario and hampers a quick evacuation in the second. Being able to evacuate quickly is a life saver. The car seat is hard to get out of fast, especially in a smoke filled (no visibility) and/or wet (slippery buckles) environment. Add to that the possibility of being at odd angles or the possibility that the parent is injured and may not be able to help the toddler and others may not realize the child is essentially locked in the wreckage and likely being exposed to deadly amounts of smoke, possible explosion, etc.
He also points out that when there is a sole survivor, given the number of children on typical flights the percentage of such survivors which are young children is unusually high. Most people think it is because they are more flexible and handle the impact better. As a sole survivor of the CRASH a child would not be able to get out him or herself for a carseat and then would not survive the smoke inhalation/fire/explosion that comes after the crash.
It is hard to really know what is safer (but we know being on a commercial aircraft is vastly safer than being well restrained in a car no matter what else

), but at least it is good to have opinions from all sides and then form your own.