I don't take gender sides in this situation. The situation is hard on both, which is why DoC has to take a very active role to try to rebalance what nature has lost. The males have been known to boom for months, always from the same spot - which is their natural behaviour. If there are no females in the area one could argue that it is the males go unfulfilled.
Thanks for all the explanation. I'm actually not sure that what we're calling fulfillment applies to these birds. In natural conditions, they don't seem so keen on mating, unlike many mammals. I can't know their state of mind, but suppose that a good crop of the special flowers simply triggers in a male an impulse to go to an elevated spot, carve out his bowls and tracks, and start booming. Then, if a female shows up, they mate because they're together and their hormones are right for it. The female, similarly, may be drawn to his booming without consciously seeking out a male. "I was just going to a concert, and you won't believe what happened!" You've noted that unmated females don't show signs of sexual deprivation. Maybe they don't feel deprived. Maybe males don't, either.
So here's the remaining question. How is booming hard on males? Maybe it's strenuous, maybe it keeps them too busy to find food. But do they boom longer if females don't appear? These males are promiscuous, meaning that they needn't stop booming after one mating. They could keep going and perhaps attract another female.
How do we know that a low frequency of mating makes either sex suffer?