I agree with your post, but I thought I'd point out about something about this particular point. Whilst the 206 is a much smaller car (particular headroom) than the Golf, and therefore there may have been issues getting 3 people over 6 foot into the 206, with the Golf there is no such issue with 3 (or 5 door cars). In fact, the 3 door Golf's have slightly more room in the back BECAUSE they don't have 5 doors (more hip/elbow/shoulder room).
The other thing is, in relation to "having babies" in the future. Having a 3 door car in my view is no worse than a 5 door. There are advantages and negatives in both.
Firstly, there is just as much room (as above) in the 3 door model. As for "placing your baby" in their baby seat, many people would find that doing this from directly in front of the seat, is much easy than doing it from beside the seat. In a 5 door you have to place your baby in sideways, in a 3 door you just push the front seat all the way forward and then step in holding your child against your chest, and then place them into the seat whilst directly looking at the seat.
Then as your child gets older, and they're able to climb into and out of the car on their own, again, having a 3 door is no more inconvenient. When you think about it, what do you do when your child is young? You flick the switch in the door jam so they can't open the door from inside the car anyway! This means, you have to get out and open the door for them!!!! What is the difference between you getting out and opening the door for them, or pushing your seat forward for them? None.
So at what age do you then trust your child to get in and out of the car by themselves? 5? Many would say that is too young, but lets use that as an example.
You've bought your car with the "What if we have a baby" view. So lets say it's only 3 months after you get your car that you get pregnant. 3 + 9 months = 1 year, plus 5 years old child = 6 years.
Will you still want to have that car after 6 years? Or would you be buying a new one?
Many many people would be buying a new one after that time anyway.
So this is why I don't understand why so many Australian's buy 5 door hatchbacks. The ratio of 5 to 3 in Australia is far higher than in Europe AND America. Why? Obviously the thinking is different...