Okay, I’m a native German. We’re famous for our very long and complex compound nouns. But we’re talking about whole sentences here. They should be simple. Why? Because there are people out there who might have trouble reading in general, or who have some kind of mental impairment. Another reason might be that your message is too complicated!
Once I attended a UX round table about “Accessibility”. Let’s say we were all expecting something different. (By the way, this very page is the result of my disappointment.) But there was one excellent contribution from a member of the audience. He told us this story: He works for a company that is specialised in creating accessible webpages. In most cases, as you probably know, the copy for a page will come from the client. In this particular case, the client was a lawyer who delivered very complicated texts. They were very - well - legal in nature. Our guy talked to the client and tried to point out that some people out there who need a lawyer don’t speak legalese, so maybe the lawyer could provide somewhat more human language? The lawyer looked at this man with disdain and told him in a very arrogant way that he had studied law! He paid for the fact that he now understands legal texts and is not prepared to give that up. So no, he refused to deliver more simple texts.
This is a great - and horrific - example of how you shouldn’t treat your audience. If I needed a lawyer, I’d be happy to find someone who speaks my language, not lawyer language. And I’d probably start looking for something I can relate to without using terms that a lawyer would.
You never know who will read your texts. Keep them simple and you’ll reach a broader audience.
By the way - providing simple and clear language will make it easier to translate your texts. At least that’s what I’ve heard. Just in case you intend to offer something like an automated translation of your page.