I've done work for country clubs and "keeping the grass short" is very expensive. The equipment and grounds crews for a 18 hole golf course are both extensive.
Most operate at least one full-service restaurant and bar area, sometimes more than one in certain seasons (ie, fine dining room and a more low-key grill type food service) and they staff them like they were going to be 3/4 full despite being empty or only 1/3 full much of the time. Food waste is huge, plus they usually feed their employees a separate meal.
A lot of clubs have big, old clubhouses that are maintenance nightmares. They don't get replaced because its a multi-million dollar expense that has to be paid for through assessments on members and there's a romantic attachment to the clubhouse because someone famous played there 100 years ago.
And your $10k initiation fee? That's a joke, $10k is for some low-rent club with a bowling-alley class snack bar. Try $100k, which usually buys stock which is refunded to members when they resign the club. It's usually $2k/month with dues, food and beverage and golf fees. And this is for a better Midwestern club, I'd double those figures on the coast, or more in certain places.
The fees aren't to keep people out, either, even if they have that effect, they're just to keep the place running. The members openly practice discrimination on who gets to join, you don't just apply for membership, you have to be asked and sponsored by a current member. But despite the veil of exclusivity, most really make ends meet by renting the place via their banquets office and low-cost "social" memberships that enable use of the foodservice areas. They need them to keep the place running.