Those P2PK were never spend they are still there.
Anyone can check it.
It's more like the chicken and the egg question.
Say you wanted to order a pizza for 10.000 BTC then you need to have 10.000 BTC it has to come from somewhere.
The same goes for the Miner, without someone having coins and making the first transactions, there would not be anything to mine.
It has to start somewhere.