Most people reading this are probably aware of the distinction in technical, legal terms. But it doesn't matter, because we're not prosecutors or the IRS.
But I still call it tax evasion colloquially, because I'm just an average Joe who can't prosecute anyone so my legal opinion doesn't matter. My judgement is not whether it's illegal, but whether it's immoral and scummy.
My neighbor, a self-employed painter, claiming his work truck (that he also uses to pull the family camper) as a depreciating business asset is tax avoidance, and I can get behind that. Ikea registering as a nonprofit with 99% overhead is tax evasion, and it's scummy.
Society, as represented by the government, wants charities to exist to assist with causes that society values, like, I suppose, architecture. They encourage this through the tax code. Society also want for-profit businesses to pay their fair share of taxes. This is blatantly a deceitful manipulation of the tax code, whether it's legal or not I don't care, they've abused the law to do things it wasn't intended to do