its like fire and ice....if paypal starts accepting btc then either btc will destroyed or paypal will collaps
Neither will happen IMO , both will coexist. Bitcoin can't be destroyed its decentralized, none controls it if paypal was intending to destroy Bitcoin they would just acquire it and then destroy it. But wait its decentralized so they can't really do that.
Bitcoin really isn't going to destroy Paypal or vice versa. After all there will always be a need for payment processors. Worst comes to worst they can just become a competitor to bitpay and coinbase etc.