Nobody's cowering from the difficulty; many of us go to Burning Man precisely because we are strongly motivated to invest in community-building, and the combination of a challenging physical environment and a wide-open social environment make it a great place to exercise and improve our skills. People very commonly come back and build interesting new community organizations in the "real world" using the skills and connections they've developed through their trips to Burning Man.
A temporary city turns out to be a great place for experimenting with new or at least different ideas about social organization, because it reduces the risk. Every organization has an opportunity to rebuild itself every year, so you can always decide to try something new, if you think it might work better than what you did before; if it fails, well, you just muddle through until it's time to go home and then try something different next year. There's a rhythm of organizational renewal and evolution that comes from the evanescence of the infrastructure. At home, organizations are never so flexible, and you get far fewer chances to go through the process of building one, so it's harder to develop the kind of experience that makes you good at it.
Furthermore, you can't underestimate the significance of the prohibition on commerce. Capitalism is such a pervasive element of everyday life that it's easy not to notice just how often our communities solve hard problems by simply retreating, and restating the problem in the form of a transaction. You can't get away with that at Burning Man; you have to engage with people socially if you want to get anything done. It's an extra layer of discipline that makes things harder, but more satisfying - not easier.