If someone starts a post with "Rationality is wrong..." or similar, I'm much more likely to downvote it than if they start it with "I've got these scenarios where standard rationality techniques seem not to work..." To this extent at least the presentation of the ideas matters as much as the content. So I hope that these rules will cause people to present their ideas more cautiously, while still posting experimentally. If you are thinking of posting something controversial, it might be worth seeking advice from the other users who you think will be interested.

Basically, I think downvotes should work as an "utter stupidity" filter.