These are called "General Anti-Avoidance" rules. The UK calls theirs a "General Anti-Abuse" rule but it's the same idea, probably better branding. The consequence of not having them is that huge corporations just don't pay your taxes because hey, what do you mean you wanted us to pay taxes, if you provide any means by which I can avoid that surely I must be intended to avoid it, right ?

It's not a "nightmare" unless your goal is to avoid paying taxes or the rule was very incompetently drafted. If you want to spend $5M figuring out how to avoid paying $5M in taxes and then moan that it was expensive, remember to factor in the price of the minuscule violins other tax payers will be needing.

> a nightmare for the business owner, and a huge boon for the legal industry (aka lawyers)

Unequivocally my experience.

Which is why people write articles like this... to draw attention to these ambiguities and how much of a boon they are for businesses with lots of resources to navigate and exploit them.

Law isn’t mathematics, it always requires interpretation. That’s why we have human judges instead of flowcharts and lookup tables.

In the EU it's typical to keep to the spirit of the law, not necessarily to the letter. It makes it less game-able. If the tax break is for research and you use it for research and not "well, technically it could be considered research if you squint hard enough", you'll be fine.