I haven't tried myself in this kind of business, but I have some friends who write keyword articles and what they say don't inspire me. It seems very discouraging to write stuff deprived of real sense. Still, I accept it as an option. When you have to think of paying your bills, keyword articles may seem a solution.

I do a lot of keyword article writing.  In my experience, the goal is to have an interesting, well thought out article that actually offers valuable information to the reader, as well as appealing to the search engines.  Many keyword article writers do just cram the words in there in such a way that the article would be as you described.  Usually, these are the lower paying content sites that accept such articles.  Most businesses or website owners who want keyword articles written for their site wouldn't settle for articles that don't make sense or have no style, as you say.  But, they'd be willing to pay more for the job to get a higher quality article out of it.  One secret I've learned in the content writing business, is that if you call yourself an SEO copywriter, you'll make a lot more money and attract better paying clients than if you call yourself a content writer, even though it's essentially the same job.