Because from here, you have the power to glide to anywhere you wish. Airtime now is nothing. Even insignificant, as you cross horizon after horizon. This,the fourth stage of flying, is probably the most intense, and mother of the 300 km plus distances flown by the curnt spate of distance mongers. Places flat and arid become paradise.
Dust devils become low saves.
You learn to fly faster, more efficiently, utilising the best part of the day for thermal development, making lightening fast decisins to leave or stay with lift, not wasting time taking the thermal to the top, or suddenly flying conservatively, slowly, as you sense a new weather system settling in, slowing the flying down. You become super-tuned to the elements, able to instantly assess conditions for the day soon after leaving launch and climbing away in your first thermal. Lesser-airtime pilots regard this stage as one of pure exultation. Those who reach it are treated with the respect they probably deserve. With so much to learn, they have come to be the perfect syntesis of technical proficiecy and intuitive ability.