Its certianly an interesting question and to be honest it could be a range of things, but having high quality staff & keeping them is one of the main areas where problems could be!
The competitive challenges which many clubs face cause them to contain cost as much as possible. Since so many cost factors like lease and utilities are pretty much fixed, the only other major cost factor are salary and wages for employees. To keep those down, staff often gets paid as little as possible, and benefits are not even a discussion item. Because of this, there is a lot of turnover.