I don't see petitions like this as demands, but as coordination mechanisms. If there are only a few industry actors with the resources to train gigantic AI models and they each want to stop but won't because they don't know if their competitors will, it's good for them all to have 1 place to say "I want to stop". Alternatively, if there are tons of industry actors racing and the only way to stop or slow down training is via governmental action - and the government won't act because they don't know how it will affect the industry - it's good to be able to point to "that one petition with 1000 highly influential signatories from the industry asking for regulation and explaining its effects".
