I literally posted a link to stats from the Office of National Statistics earlier on. The fact you didn't read it shows your ignorance to the idea you might actually be wrong about something.
It's 8.3 times because that's how much houses cost compared to what people earn. It's nothing to do with people taking loans they can't afford, it's literally the only option if you want to own a house.
You can throw as much conjecture at it as you like, it's right there in black and white in front of you.