I did post right at the start of the thread. (My personal circumstances are that we live near the sea and I think we'd be daft not to give DD a way of helping herself should she ever get into difficulty, as a quick recap.)
There are a few things that occurred to me reading the thread.
Firstly, I too would like to see the stats on over-confident children getting into trouble. I do also think though that part of teaching your kids how to be safe in water is respect for water. I see it the same way as I do teaching dd to be safe around dogs. She loves dogs, gives ours huge hugs, so part of my job as her parent to keep her safe is teaching her to ask other people before she approaches their dog, and teaching her that not all dogs like to be touched etc. So every time we go swimming I also remind her that she's not to go swimming if there isn't anyone around, for example.
Neither do I see it as acceptable to stop watching her like a hawk because she can swim a few strokes. Adults who are good swimmers drown. Someone mentioned kids getting into trouble while parents sat around reading and trusting they could swim (paraphrasing madly I know, because I can't remember exactly how it was phrased). Well, more fool you as a parent if that's your attitude. Teaching your child to swim is not and should never be a replacement for supervision.
Also, there are people confidently claiming they don't live near any body of water. Well, I do see it as even more important to learn if you live near something obvious like a lake or the sea. But I wouldn't be too complacent about not living near one. As an example, at a zoo we were at fairly recently a four year old climbed a barrier and fell into the penguin pool. Now, the same arguments as above apply - supervision was obviously lacking if the kid had time to do that etc etc. The fact remains though that she was suddenly submersed in water. A member of the public went in for her. Thing is, mostly people in that situation look for a keeper rather than act. If there isn't one about, you don't have much time. Those extra few seconds where your child doesn't panic because they know the feeling of being underwater might give you a few precious extra seconds while someone reacts (looks for a keeper, realises there isn't anyone, looks to see what other people are doing, realises no-one is acting and takes action). If you go to the zoo, look at the number of enclosures surrounded by water. I'll bet most of them are safely fenced, but I'll also bet that most of those barriers are climbed on by kids at some point, not to climb over but to get a better look. One missed step and there's your accident. My point is there are more bodies of water around than you think, in unlikely places. Saying "I don't live near one so it's not a problem" is just as complacent, in my view, as saying "my child can swim therefore I don't need to watch them."
However, I do think some really valid points have been raised. Health issues which might affect things, money is obviously a key one (I'm bloody lucky - grandparents pay for dd's lessons or we'd be struggling to scrape the cash together), access is also clearly going to be critical. I just happen to think that if all these are not relevant, and of course you can never be sure if they are, then yes, you're a bit daft not to teach your kid to swim.