I am aware of the history. But your assertion that only Iran wishes to attack Israel is untrue. Al-Qaedas very foundational idea was to hurt the Saudi government for allying with the US (and by extension Israel). And these rebels are all former Al-Qaeda or worse.

You think they will be pro-Western before they will be anti-Israel? It's a very risky gamble to make.

They don‘t have to be pro anything. Al Julani’s family themselves had to flee the Golan heights due to Israel’s occupation, so I doubt they‘ll become best friends. All I‘m saying is it weakens Iran and that‘s a good thing. Few in the area are enthusiastic about Israel, but most of them are at a point where they just want to move on.

But most of the countries in the area are dictatorships, where they don't need to abide by public sentiment. Public sentiment in almost all these countries is that they want to stop what Israel is doing to the Palestinians. Egypt's one and only election was to elect a leader who promised to change that, and he was of course deposed by the military (with Israeli help). If the rebels do set up a government where the voices of the people are heard, it will be bad for Israel (and vis a vis, good for Iran, presumably).