Making things illegal, or, rather, enforcing those laws, is an uphill battle if you don't also structure the incentives in such a way that it's easier to follow them than to break them.

Also what does "make corruption illegal" even mean? Corruption takes many forms, and there will always be loopholes through which the most savvy can escape legal repercussions. I would much rather structure things so not being corrupt is just the easier, better, more natural choice. That's also not easy, but sounds more achievable to me.