Fully destroying bitcoin will need a lot of work and not just one person can do all of those. There has to be a group of highly intellectual people who can bypass all the algorithms of bitcoin and doesnt sound so possible.
Exactly, destroying bitcoin or removing it forever is just impossible to say because a very special security is provided to bitcoin holders and such algorithms are made which are not easy to break or you can consider it as impossible, but still people do fear from it.
If someone has to destroy bitcoin they need to break such unbreakable algorithms which is totally impossible and a very difficult task. Bitcoin is giving benefits to its holders by giving them profit from their invested money.