HF20 wouldn't have happened without the witness' vote. How did the witnesses decide to run the HF without proper information? Couldn't they have figured out that the system needed to be tested? There ARE people on steemit like @reggaemuffin who claim to have expertise with software releases and want to be witnesses and also know what needs to be done before something is sprung on hundreds of thousands of users.
I hope everyone learned their lesson.
I really think they did as there is a lot of talk about testing before SMT's come out, which will be our next major update in March (2019)