I think intentional obscurity is probably rare. I think it's more of an evolutionary explanation. We don't get old age illnesses in old age because they're useful, preventing old age illness is just less useful than preventing prime age illness.

Clarity is difficult, and if it rarely makes a difference to businesses then it gets left out.

One reason clarity is difficult is that it requires narrowing what you say. Measurable accountable and integrated business software solutions. From the outside this sounds pointless and meaningless. From the inside it sounds nice and wide, encompassing everything they do. Better too broad than too narrow.

People's CVs sometimes have the same problem, resistance to limiting language.

The reason it doesn't matter is the way they get business. In face-to-face sales, clarity is surprisingly unimportant. It can even hurt by allowing prospects to raise objections without the presence of a salesman. Basically, the company's marketing doesn't matter, so it sucks.