But if people REALLY want to play those games, I'll play them. Most of the time, people seem quite surprised at the reasons I give, and are more than willing to play a game that everyone can get on board with.
There are, however, PEOPLE I will not play with, and the OP would be a perfect example: people who will refuse to play games simply because they don't win enough. There's no positives such people bring to the table, I'm afraid ... it's best to simply make sure I'm always playing a game they're not, and I purposefully do not invite such people to our regular Game Night events.
Most normal people don't think about game design. This is why they have house rules in Monopoly about the putting all fines in a pot and landing on the whatever it was called square to win the pot. It unbalances the game, and keeps money out of circulation (the bank can run out).
On your latter point, if you are in a group of 5 people and can't ever win 1 in 5 games, how much fun are you having?
Now somebody could look at it as training, you have to pay your dues to get good at the game. For example, I spent 6 months playing darts in my boss's office every day, getting my butt handed to me. Then I started winning, and became one of the top players in the group.
On the other hand, I suck at games like Chess. While I am a smart guy, I don't think moves ahead or any of that mumbo jumbo. I therefore don't enjoy the experience of always losing to anybody with any skill for the game (which are really the only people who play chess).
In a way, I think you have it backwards. A person who doesn't want to play a game because they don't win enough/never win, knows they are not a proper competitor for you and would drag you down. They are effectively advocating playing a game where both of you can enjoy it (or at least negating 1 title that you don't share in common).