A couple of thoughts from a UK perspective.
'Out of play' areas have implications for wildlife (ground nesting birds, insects, wild flowers, butterflies, mice, voles etc etc etc and are thus an opportunity for clubs to do and be seen to be doing something for the environment.
They also have maintenance implications however, for if you ignore 'out of play' areas completely or near completely then it won't be long before the self-seeding trees, scrub and brush takes over and then the 'fun' and expense begins in removing the now large self-seeders as grazing animals, which used to keep such areas under some control, ain't frequent on many courses these days (unfortunately).
Give such areas an annual good cut or two at the right time of year, after the ground nesting birds etc etc have done their bit, and the self-seeders should be kept at bay.
One of the better examples of how this operates is Stinchcombe Hill in Gloucestershire. Gorgeous looking high native grasses swaying gently in the wind but well off the fairway and full of skylarks etc until cut in late summer.
atb