A society with limited resources/etc will support an untested technology with only symbolic value just fine if it's cheap enough.
And RAMA just pointed out it can be quite cheap - for a society that has colonised its solar system (a very probable step for an intelligent/technological species - we're on the verge of doing it).
We are about a hundred years short of really beginning the process and at least a thousand short of completing it. It is far from certain along that progression that we actually WILL colonize the solar system, though most of us would like to think so.
What's significant is that we cannot speculate on what a system-spanning society will or will not do with its technology because that society looks dramatically different from ours and has different pressures and priorities. It would also have different capabilities; by the time they have the ability to feasibly construct an interstellar mission, they might not NEED to.
BTW, humans do have an exploratory imperative
In pursuit of a concrete objective, yes. We trek across the plains in search of useable farmland, we sail across an ocean in search of trade routes, gold and other natural resources.
The one thing we have NEVER done is conducted generation-long exploration missions purely out of curiosity. That's the thing about planetary exploration: we haven't figured out yet how to exploit the resources of the other planets, so there's no huge rush of people/governments trying to colonize it now. An interstellar voyage that has no prospects at all to return those resources to Earth (Mars, Ganymede, the People's Republic of Saturn, etc) would be a symbolic gesture AT MOST.
As for the rest of humanity: in the long term, it becomes irrelevant - just ask those half-monkeys who died in that cave in Africa after their betters left.
You DO know people still live in Africa, right?