In my experience, foiling a little bow down is more stable than foiling a little bow up. As the boat lifts in that attitude, it doesn't build towards increasing lift and spiraling up until crashing down. Oracle's AC72 often was a little bow down as well.

This is different from "foiling" with C boards in foil assist configurations where you want the bow up all the time and the sterns still planted in the water.

Maybe they want perfectly level flight, but I think they looked very good and very in control, something everyone will want and need when sailing a 3 ton, 40 foot cat.