Assad is not Shia. Alawites are not Shia in any meaningful sense. Somewhat minor nitpick but I mention it because you seem to be inserting in some sectarian solidarity that doesn't exist..
There is one thing i find rather odd though. From what ive observed, its rather puzzling that those people who were clamouring and cheering for Saddam's Sunnis brutal baath party regime to be toppled in Iraq by the US/West are actually the ones now supporting the very same Assad Shia brutal baathist regime in Syria. I understand that there is a sectarian issue(Sunni vs Shia) in the middle east, but still its an interesting thing to see and something to ponder on. Guess everyone has their religious/ideological/cultural bias.
The opinions of internet commentators don't matter but to me it seems normal that people are more hesitant to support these "revolutions" than they were 20 years ago is because they can now evaluate the results of them in Iraq, Libya, Sudan etc.
As for the Iranian government's intentions, they also seem perfectly rational given their known political objectives. They need the corridor to Lebanon, they don't want their ideological opponents to have base, and they have concern about the safety of religious minorities (if you don't believe them at least you believe they are concerned about the Shia minority). Whether this set of objectives is moral is a different dispute. Could they could achieve this while pushing the Assad regime to be more inclusive or leave altogether? I don't think that would be easy and I don't know to what extent they tried.