I'm not going to play guessing games regarding the future of Bitcoin. It is however a fact that as the value of something increases, the effort that goes into protecting that thing increases.
Actually, as has been stated, for the value to increase, it will require wider adoption. Wider adoption means the value is spread among more users. And the key point here is: when you have 1 million users who possess a digital file that contains 100x where x is valued at y, or 100 million users who possess a digital file that contains 1x where x is valued at 100y, you still have the same total value per user, and thus, rationally, each user applies the same measures to safeguard it, regardless of the value of a single unit.
Honestly, is that your argument? That the increased value of Bitcoins will result in an overall increased effort to safeguard it?