The premise of this thread is spot on, even if the examples are slightly weak.

You propose that some one comes up with a "better" bitcoin. However, that is not required. They need only come up with a "more accepted/useful" bitcoin. That is not so far fetched as the forum consensus would point out.

For example, the current bitcoin implementation is very popular among Crypto-Anarchists and libertarian revolutionaries. As an investor you are betting that this community can sway the masses to support "their idea" of better money.

A few days ago there was someone of a more liberal bent that proposed some monetary policy changes that were "fairer" from a liberal perspective.

Others have proposed changes that seem better if you prefer the idea of a zero inflation/deflation money.

All could be implemented with minor changes to the bitcoin code base. (I am a coder by trade.) So as an investor you would be betting on which group is more likely to build the most valuable consensus.

Unless you buy into the idea that there is a build in demand for bitcoins just because they exist as a limited commodity. In that case, I've got some things I think you'll be interested in...