What would have happened if Bitcoin had been Proof-of-Stake from the beginning?

What would have happened if Bitcoin had transitioned to 100% Proof-of-Stake sometime in the past few years?

If Bitcoin was PoS right now, what would you tell someone who says Bitcoin isn't real money because it's not backed by anything and people just get it for free?

What would you tell someone who asks where Bitcoin comes from and how they can get some? 

Most people's first assumption was that Bitcoin was a scam, even when anyone could mine it with a laptop.  So how many people would have adopted Bitcoin if the answer was "You can only get Bitcoin by giving real money to the few people who already have bitcoins, and then you can buy in and become a seller yourself!"

Would the average person be more or less inclined to view Bitcoin as a pyramid scheme?

Miners pay for the electricity they use, so the electricity is theirs to do whatever they want with it.  You can talk about waste, but the miners are only "wasting" their own money.  It doesn't affect you negatively, and the miners obviously think it's worth it.  The people "wasting" their own money don't feel like they're wasting anything, and your opinion has no weight regarding their personal choices.  And if they spend a certain amount of money mining, and then sell their mined coins for more than they spent, then they've profited. 

What definition of "waste" are you using that applies to increasing your supply?  "We had 2 dollars, but you went out and got 2 more dollars!  Now we have 4 dollars, which means you're wasting dollars!"  That's what you're saying, when you say mining is wasteful.