As I understand it, the root reason for the Muslim opposition/intolerance/persecution of the Baha'is is rooted in Muhammad's teachings.

He declared that he was one of the long list of God's prophets, which included among others Abraham, Jesus, and Siddhartha Buddha (the original Buddha), and that he was the last prophet, there would be no more.

Then along comes Baha'u'llah perhaps 600 years later and announces that he is one of that long string of holy prophets, which of course flies directly in the face of Muhammad's self-proclaimed position as the last (and by implication the most authoritative) of the line.

That's the Muslim beef: impiety toward Muhammad. All the other claims of heresy, impiety, and so forth are propaganda added later. It's not about religious practices, nor even about religious views; it's a territorial catfight.

Dave Oesterreich