In my argument for AV I used the concept of treating it as a restaurant in which everyone orders from the menu I then ended with a brief point about PR, which I've been taken to task over -
"With first past the post the largest group orders chicken so everyone gets chicken; in AV the majority orders chicken, but everyone still gets chicken. Wouldn't it be better if those who ordered chicken got chicken and those who ordered vegetarian got that etc.?"
Well yes except that's not PR. As I said the first group the waiters reach get all the chicken, then the next get the fish the next the vegetarian and so on. However that analogy needs tweaking:
Under a PR system the menu is presented as follows:
Some might fancy steak others salmon or a curry ; but you can't choose steak or salmon you can only pick Meat, Fish, or Vegetarian. So all the steak lovers pick Meat, the salmon lovers Fish and the curry lovers Vegetarian.
The result: All the Meat group get chicken or beef, the Fish group trout, and the Vegetarian group pasta. It's possible the majority got what they wanted as the majority of the Meat group might have chosen chicken etc.; but we don't know and can't tell.
So just like FPTP we have a system by which the majority might not want that result. Is this somehow fairer because at least the Meat group got meat, the Fish group fish and the Vegetarian group a vegetarian option? Not if you hate chicken, beef, trout, or pasta.