This.
I've met them and they told me they are considered "lightweight" Muslims. The more extreme Sunnis (Wahabis) consider Shiites heretics.
Shia are another sect altogether (in which you will have moderates and fundamentalists). All Sunni's consider Shia to be heretics. The Wahhabi's and the Salafi's are just more open and aggressive in their dislike towards the Shia.
IMO, the Shia are useful allies in the fight against radical Islam (which is almost entirely a Sunni Muslim problem) since they know first hand how dangerous Sunni extremists are. I'd like to see the Western nations become more friendly with Assad, Iran and other Shia leaders/nations - much like what Russia and Putin have done.
The cultural Muslims are the first to take offense though. The radicals don't because they know there's a lot of truth in the criticism. And the cultural/moderates don't turn in all the terror planning antiAmerica spouting radicals they know.
The cultural Muslims take offence because they have little knowledge of the religion and have an idealistic opinion of it (much like some Western liberals do too). Therefore, they think the criticism made against Islam is because of bigotry and a lack of understanding. They haven't actually researched their own religion and analyzed it from any rational perspective. The biggest problem I have with Islam is the political aspect of the religion. It isn't just a religious philosophy, it has several components to it that when combined, can make it extremely unpleasant and dangerous - both to the actual believer and to outsiders.