I'm on Twitter most every day; I don't follow Elon Musk (I try not to follow any big twitter accounts, rather than curate interesting smaller accounts); I didn't see the poll until two days after it was already closed; I think it's fair to say that most people who saw the poll were

a) Either followers of Elon

b) People the Twitter Algorithm decided were most likely to interact with it -- I.E. people who would be interested in what Elon has to say

Just because Elon tweeted something doesn't mean all of Twitter saw it.