Maps have been drawn and re-drawn thousands of times throughout history. In this case, I have serious doubts that an entire culture will be wiped off the face of the earth.
(I like drawing parallels to the colonists' practices against the native Americans back in the 18th and 19th centuries because it invites humility and self-reflection into the mix)
The truth is that their culture won't be the same whether we settle on a two-state solution or wipe them off the map. Take a look at the Cheyenne tribe. They were given their reservations - sovereign states in and of themselves - and yet under the overpowering economic and societal influence of their neighbors (casinos, cigarettes and booze, anyone?), have been reduced to rich families of the same culture as the US. They have a history that they hold on to and strive to understand, but they've succumbed to modern conveniences over the "live off the land" mantra of their predecessors.
At least if Palestinians have a state, they can be represented in their government, they can have a say on the world stage, they'll be recognized throughout the middle east (which is important for the west) and history will look somewhat favorably on the situation. They'll be closer to their government rather than being ostracized (which would lead to more radicalism I'm sure).