The big owners of bitcoin can destroy because of volatility of bitcoin when the owner did not use his bitcoin anymore or forgot their password the moment they did not recover it is to be consider lost bitcoin and when the number of bitcoin circulating in the market became lost or stagnant thet would be the start that bitcoin will be destroy.
Bitcoin is unstoppable no one can destroy it and this is the behavior of bitcoin that it attracted it haters toward it JP is the best example in front of you and more of it bitcoin is changing lives of people so that people are now its defender people start buying as its prices goes down and all are united because profit is same for everyone and thats very good, bitcoin has no enemies now excepts jealous people.