I don't think many people defend the government of Iran, they just don't want to start a war with them and feel that if there is something wrong with the Iranian government, then the Iranians should bloody well sort it out themselves.
Much cleaner that way.
Who told you you get to pick what government you like and what not, and act in another sovereign country? And who said the population of other countries want you to interfere with their affairs? You can find anti-government people in any country, including yours. Even anti-government groups and parties.
That doesn't mean the general public of said countries want someone to invade and take care of their government for them.
I'm not defending Iran, and I think it's high time for the whole bloody revolutionary government to be thrown out and replaced with a democracy. That said, I find the claims of the US and Israel to be somewhat suspect.
This is patently false.