Lol. Is this a serious question?
Gerrymandering and propaganda is probably the answer.
Gerrymandering is obvious (look at popular vote totals within states and the distribution of seats). In wisconsin, dems have to win by like +10 to split the house. Not even a fair fight.
But more concerning is that how can you convince people to vote for something reasonable, when they show you signs that they don't believe reasonable and established truths? Don't polls show something like 70% of republicans believe significant voter fraud just occurred? 70% What hope can you have for a reasonable, nuanced ballot initiative when the people voting aren't even in touch with reality? It's like trying to convince 6 year olds who still believe in Santa to raise taxes so that police officers can get pain. I mean its a reasonable proposition, but 6 year olds aren't going to go for that; they still believe in santa.
Honestly the better question to ask is how does any ballot initiative pass at all in red states, other than the ones that are all about fucking over thy neighbor?