Because success in life is mostly based on the size of your wallet, and games are supposed to be an escape from life. It sucks when that albatross follows you into your fantasy life.
There are plenty of other games, I don't see why there couldn't be one about traveling in the real world.
Would you frown upon Geocaching as well?
I suppose it is subjective, but it seems to be a pretty much near-universal sentiment among gamers I know that "pay to win" sucks.