Co-founder is just a marketing name and has no meaning in reality, actions do. Looking at this he provided in money which was likely to ruin his business by overspending it and greater minds prevailed in the end (I'm not saying paypal is a good thing or not). Why they made him CEO I cannot fathem but it has probably something to do with the bullying behaviour he is known for.

I've been named co-founder once but as soon as its usefulness ran out it got removed from the website (nothing else changed).

Edit; needed to be response to parent, sorry.