If the government wants a tax to be paid they need to make it simple and unconditional. If there are loopholes or ways to legally avoid it, they will be discovered and people will take advantage of them.
One who exploits a bug is a hacker. An example of a life-hack is to arrange things to have lower taxation than those who wrote the laws were expecting.
But just as bugs in software are not meant to be exploited even though they can be, there are many loopholes in laws that are not meant to be exploited even though they can be.
Unless the law has a generic catch-all for tax minimisation schemes*, such minimisation may be legal, and yet frowned upon because it wasn't meant to be legal. Or even if it was meant to be legal, but you're rich and the general public thinks you're being unreasonable.
* I think the UK does? Or at least that's what it looked like HMRC was saying last time I was able to file my own taxes there…
We can't write bug-free software even with unit tests and formal methods, what hope does a legislative body have? Debate before a law passes may be like code-review (and for big bills this debate is essentially "LGTM"), but most-to-all of the testing is in production: https://en.wikipedia.org/wiki/Test_case_(law)
This is not to say that no deliberate tax doges, they certainly do exist, but there's a lot of bugs too.