Grass is just too hard to maintain compared to HC or clay courts. Even Wimbledon had to make sacrifices(by using a different type of grass, which slowed it down) to make it easier to maintain.
It can't be that
hard to maintain or grass courts wouldn't have preponderated for the best part of the last century.
the grass season should be longer. And it should be hard courts rather than clay that take the hit. 35% hard, 25% clay, 25% grass, 15% indoor carpet - the last idiotically phased out by the ATP - would be far more balanced & better for the players' health than the rubbishy season we have now.