Some consumers are short-sighted, greedy and selfish.
Extend yourself a little and they'll want a lot.
Offer a free drink in the restaurant one night and they're angry that it's not there the next.
The nuts in first class weren't warm!
The challenge of winning more than your fair share of the market is that the best available strategy–providing remarkable service and an honest human connection–will be abused by a few people you work with.
You have three choices: put up with the whiners, write off everyone, or, deliberately exclude the ungrateful curs.
Firing the customers you can't possibly please gives you the bandwidth and resources to coddle the ones that truly deserve your attention and repay you with referrals, applause and loyalty.