Top 5 reasons:
1) H2: one of the ramifications of bot-generated content is precisely PAAs. A bunch of H2 with super repetitive (or random) content. Keywords in H2 multiple times...so predictable.
2) Totally random stuff: you ask the robot to write an article about horses. You use a keyword scraper and everything is created automatically. Result: your 2500 word article is garbage that talks about horses, seahorses, zoophilia, trojans and anything else that was picked up by the bot.
3) Extremely repetitive content: unfortunately mankind has not developed enough to create a really competent robot writer. We are at the beginning of this, it is understandable, if you have ever read a text created by a robot, you know that probably the same facts will be repeated three or four times in the same post. Now imagine 3 facts that are repeated 4 times in the post...12 parts of your post is repetitive content and extremely monotonous for a human reader.
4) Low quality: continuing what I mentioned above about repetitive content. Your text will be low quality, random stuff + repeated facts. How does Google know that your text is junk? Well, the bounce rate is high, people won't come back to your site and they won't be interested in reading another post either. Oh, and probably the appearance of these sites is pathetic, self-generated or self-added images (often unrelated to the topic), or worse: youtube videos that also have nothing to do with the situation described.
5) Fake News: at the peak of the fight against lies propagated on the internet, do you really want to create hundreds or thousands of posts without reviewing anything? These automatically generated posts are full of lies, wrong historical facts, misinformation...and this all puts you on Google's radar that is on a crusade against sites that spread lies.
Advice for everyone who wants to do something really serious and not just a game of cat and mouse with Google: start using this as it should be used, it's just a tool, a friend to help you, review everything this tool generates, write a few paragraphs manually, invest your time building a site with really nice design and not just a standard junk with a ordinary theme.
Don't create articles full of repetitive H2. Don't create articles with only questions and answers. Don't pollute your article with 500x the keyword, this attracts attention in a negative way. Check all the information generated. Read carefully and see if it makes sense, correct informational and grammatical errors. If a term is repeated too much, look for synonyms, the readability of your article is unbearable with these machines writing the same word over and over again, etc.
