I would even accept it if they told me $15,000 to $40,000 because I believe that many countries will accept bitcoin, but $100,000 in 4 or less than 4 years would be an exaggeration, I think.
Many countries to accept Bitcoin? I think you should look up the difference between countries accepting Bitcoin, and countries legalizing Bitcoin usage ~ these are two very different things.
There is really no way I can see whatever country to accept Bitcoin at a certain point. If they ever happen to stimulate digital currencies, they will develop their own centralized version of Bitcoin.
Governments aren't interested in handing over people the financial freedom they are so badly looking for. They want to remain the central authority in each and every aspect, and that's obviously not possible with Bitcoin.