I think you've misread the thread. The idea is not to advocate to PayPal that they accept Bitcoin, it is to advocate to a certain business that they accept Bitcoin rather than PayPal.

But to answer your tangential question - if Bitcoin does what we think it will do over the next several years, than PayPal's only chance for survival would be to accept Bitcoin. For if they are to not adopt Bitcoin, they will surely be put out of business.