Why aren't one state solution advocates more concerned about Islamism?

The only arguments I hear for a one state solution go something like this:

(1) The Palestinians are entitled to a right of return because they have a valid claim to the land. Some of them even still have the keys to their home.

(2) A two state solution is a euphemism for apartheid whereas a one state solution governed by pluralism, tolerance, and equality between Arabs and Jews isn't just a western ideal but instead a universal human ideal. Palestinian resent is a result of this injustice, and so the resent will continue as until there is justice.

My main counter point is this:

(1) The fact that 66% of Palestinians believe the punishment for apostasy is death is all the proof we need to show that the ideal of free and open society is not universal. There is no Israeli policy that caused the Palestinians to think this way -- In fact it works against Israel's interests in every single way. This is self inflicted oppression that's purely the result of Islamic fundamentalism.

(2) An unconditional right of return for all Palestinians is a security threat to apostates living in Israel. While I'm sympathetic to a right of return, I'm not willing to empower Islamism in the name of decolonization.

(3) If present day Palestine is not a safe haven for the Salman Rushdies of the world then a historic Palestine won't be either. Salman Rushdie was about to give a lecture on how the west is a safe haven for exiled writers at an ideas festival before he was stabbed on stage by a a would be assassin.

(4) Islamism is an existential threat to a free an open society, and a one state solution should be contingent upon it's defeat. The freedom to criticize religion in the west is guaranteed by the law, but it's also guaranteed by the fact that our neighbors don't issue death warrants for the crime of criticizing Islam. The Mormon church didn't issue death warrants in response to satirical Broadway plays, instead they put ads in the New Yorker.

(5) It's up to the Palestinians whether they want to bring an end to Islamism.

Main source: https://www.pewresearch.org/religion/2013/04/30/the-worlds-muslims-religion-politics-society-beliefs-about-sharia/

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