The joke is that Linux blocks this by not doing it at all. Which is why people should switch to Linux. Which is a good idea. But that’s up to the people.

I think the point being made is that company staff shouldn’t be leaving five-star reviews on products they, themselves, work on. Whether they do it because they love the product, or a company suit told them to. Personally, I think it’s fine to try and convince people to use your/your company’s software, but giving yourself a five-star review to do so is downright pathetic.