Like you, I agree that secular unification is the obvious solution to this conflict. However, I am unwilling to ignore the role that religious extremism has historically played in preventing that outcome. It actually saddens me to once again see leftists abandon their first principles in favor of brain dead revolutionary fan service.
Israel is absolutely an apartheid state which has brutalized Gaza far beyond what is necessary for security, retribution or deterrence. They should be condemned and sanctioned soundly for this. However, if you espouse support for secular unification, then you must also acknowledge that the Islamic opposition to Jewish co-governance is a major force preventing this outcome, and it has been that way since before the state of Israel has existed.