You will always have bad people. The more people that exploit the system, the faster the system will change to be more 'fair', otherwise you're just handicapping yourself. Look at all the patent lawsuits. As they said in my business ethics class: ethics schmethics.
(1) It's not clear that acting unethically will lead to better rules and more ethical outcomes, in general [and actually, in some cases the opposite will happen - if you're corrupt it makes it easier for others to be corrupt]
(2) Handicapping yourself is the whole idea behind ethics and morality. Sometimes it's more important to do the right thing than the selfish thing.
Attitudes like yours are so disheartening to read. I totally disagree with your sentiment.