People are now actually doing this if you look at Yobit and other exchanges people are more than willing to trade their bitcoin to other altcoin because they believe that one of these altcoins can and will rise to be one of the top crypto currency and be accepted by merchants
i really really struggle to believe that. all they're after is more bitcoin. anyone who thinks their pet coin is gonna take over the world is gonna have a bad time.
before anything else can happen, one crypto has to break out into the wider world. it's no good staying in the weird little corner it's in now.
i think there'll be alts that fulfill different purposes but bitcoin will always be the one. i also think that not a single one of the current alts will be anything other than dead and forgotten in a decade.