I think I understand what you're trying to say here -- and I don't want to dismiss out of hand the virtue of that lifestyle, especially for the individual who commits to it -- but ultimately I don't think it's a meaningful "challenge to the values of the world." And I don't think it has that much value to most others as a spiritual example.

It's all too easy to walk by those people and dismiss them as having a heroic vocation ("not for someone like me") or write them off as mad.

To me, the priest who lives among the poor, sharing their poverty, and agitating on their behalf -- again, while remaining true to the tenets of his faith -- has far more to say about why people should care about the "out there" at all. The priestess whose courage and compassion in standing beside the sick and the abused, helping them find healing, demonstrates the love of the Divine far more powerfully than the one walled up in a convent on the edge of town.

To a less dramatic extent, simply living one's life in the community while demonstrating the virtues of one's faith show that it's possible to be both "worldly" and connected to the Divine. That the extra effort it takes to make and nurture that connection can have a real, positive impact on daily life and create a more loving, just, and beautiful world for all.