Palestinians and Israelis would have no trouble living together. It's Zionists that have trouble with modern multicultural societies.
Which Arab majority state would you hold out as a model for multicultural societies?
Maybe some day the Arabs will leave behind their extreme racism and build secular democracies. In that future day then perhaps a one-state solution would be possible, with everybody living together in a secular multi-cultural democracy. That would be nice.
But that isn't what would happen right now. In every instance, including in the Palestinian Authority, when the Arabs have had a majority they have used it to marginalize and ultimately ethnically cleanse Jews. It has happened in every single Arab state and in the Palestinian Authority. A significant percentage of the Arab population continues to believe that violence against Jews is practically a religious duty.
This is unlike in Israel where the Jewish majority built a secular democracy that offered full citizenship and equality to the Arab minority living there.
If you want a one state solution, some day, you're going to have to explain how we get around a hundred years of Arab violence against Jews that shows only vague signs of letting up. There were some promising inklings in Egypt recently that things might turn around -- but it hasn't yet, and when it does, it'll surely take at least a couple of generations become normal. At that point, and not at any point before that, it might be possible to talk about a one state solution.
Until then "one state solution" is code for "annihilate all the Jews". You know it, and I know it, and everybody else knows it.