because you are trying to tell things and show others you are well educated and having knowledge, and you are doing your best but unfortunately it is in the reverse direction.
There are big differences beween Sunni Muslims and Shia, on the net there is a good websit and I quote the following:
"This allegation however, finally found a place of acceptance in the capital of the previously Iranian (Persian) Empire, Al-Madayen, more easily than in the other regions of the Islamic Empire at that time, especially since Al-Hussain, second son of Ali, was then married to the daughter of the last Iranian Emperor."
You can copy the above qout and you will find the website.