You may not know anyone, but I can assure you that there are many people who take advantage of the low price. In one area near our Costco there is a lot of construction going on and at lunch time and afternoon there are line ups of construction workers taking advantage of low prices, so your assurances are not reassuring to me at all. There is also the matter of those that bring guests into Costco, they are not allowed to buy, but the do on the members card and they also take advantage of the low cost fast food items. Maybe you like supporting those that don't pay a membership fee, but i don't.
The food court does not ask for a membership card when you purchase. Costco does not ask for a membership card when you enter though the exit either. Many costco in warm climates even have their foodcourt totally outside. You are also allowed to use Costcos pharmacy without being a member.