Once, mankind were wanderers and gatherers travelling almost thousands and thousands of miles in a lifetime, not knowing where the journey will take them. Our ancestors came down from the trees in the African savannah to discover the vast land all around. Thousands of years later they travelled from island to island in the pacific ocean, having already conquered the African, European and Asian continent by feet, not knowing that Earth will one day be seen not as endless, but just as a small ball of dust in a much vaster universe. Another few thousand years later mankind became settlers, building civilisations all around the world. Large empires rose and felt, the world was discovered a second time (much faster now) and the world view changed dramatically.
Today we are even another thousand years further - now reaching for the stars. But access to space is costly and dangerous. Maybe it's not yet time for such a step - and therefore Mars (maybe the most discussed "next step" into space) is believed to be just beyond our range by many critics. But let me cite Carl Sagan to put our history against this:
"Our ancestors walked from East Africa to Novaya Zemlya and Ayers Rock and Patagonia, hunted elephants with stone spearpoints, traversed the polar seas in open boats 7,000 years ago, circumnavigated the Earth propelled by nothing but wind, walked the Moon a decade after entering space - and we are daunted by a voyage to Mars?"
We have been wonderers for all time, and still are. It is part of our deepest nature to discover new frontiers and reach for the (seemingly) unreachable. I don't want to say that discarding these things would stop our evolution - but it will most likely slow it down. The greatest frontiers have always lead to new, prior unsought discoveries and developments.