Art is great. Let's always be trying to discover newer forms of art.
It turns out their way of progressing did not bear friut and peasant societies were much faster. That's life.
Why are you only obsessed with new things? Why cannot the legacy be cultivated?
It turns out that pastoral life did bear its fruits, you simply dismiss those. For one, the most important fruit: those people are still around. No that is life, not "progress for the sake of progress".
Legacy absolutely should be cultivated and remembered. But never at the cost of rejecting further motion.
Pastoral life was great why it was going on (even remembering all the raids and slavery stuff), but then it could not go on anymore since peasants learned how to build walls and posts and forts. And had a good reason to do so.
How do you know we were always going forward in the right direction? How do you know sometimes we don't need to go back? DDT? CFC gases? There lots of examples even from the recent times.
Why do you think people in the pastoral civilizations didn't exercise their curiosity? Just because they didn't built things you fancy? Didn't they create things, like art, just for the sake of beauty? Isn't that a kind of exercising curiosity, Didn't they develop and learn methods to live in harsh environments, to use the plants as medicine, etc. Isn't that kind of learning valuable, because it does not lead (as quickly) to creation machines doing fancy flashing stuff? they were living, and progressing in a different pace in possibly different directions.
Your attitude is not simply colonialist, but also lack respect for many forms of knowledge, only for these are not on the modern technocratic urbanite's tool-belt makes it especially narrow-minded.