you are right, one aspect nevertheless: there could be a successor to bitcoin in its current form ... then it's clear that everyone will jump ship. i think, quite a few of those who have "missed" bitcoin so far think, that they'll simply wait for this new incarnation and hold back their investment.
That would be ill-advised: Bitcoin is likely to be the best or only way to get into the successor, or at the very least, the best or only way to get into it early on.
Also, cross that bridge if we get there. for the time being, bitcoin is the cadillac of crypto currencies... (It's just an expression.. well I mean back when cadillac was the shit)