playing fields every 7-8 years regardless of how much activity takes place on the field because the roots tend to clump together tightly, then leave patches of grass between the clumps with very little root structure under the grass between the clumps. It's just a feature/quirk of how a lawn or field of bluegrass grows. When you have an old bluegrass playing field, and when it gets wet and soft, you'll rip up big sections of turf.

There are no such issues with a new field/lawn, even when wet.