well it kinda makes sense cause otherwise you would basically have unlimited caps. dont get me wrong, that would be awesome to be able to buy everything, but thats not how the game is meant to be.
One good tip for people who make high luck a cornerstone of their strategy is to play blackjack until you are close to that casino's ban limit, save, then play-reload slots until you get the jackpot you are after. This is alot of annoyance for an extra 6k chips though since the game is not that cash-intensive (I've never needed more than the 30k or so I get from casinos before being banned).
When you have 10 luck (8 + implant + nightwear), then you can generally hit a big jackpot pretty easily. I have not ever earned enough to be banned before having hit a jackpot of 8k I think. Normally I can get at least one of the casinos to hit the tripple-orange for 32k.
also: At higher luck levels, blackjact is dramatically different. With 5 luck I was earning chips very slowly and having to reload a lot. With 10 luck I was winning 10 hands in a row regularly, and making 21 every 4 hands (getting a natural every 8 hands or so).