Its happened much too frequently to be uncommon. I've seen it happen right in front of my eyes, its been reported recently in the newspapers, occuring in Malaysian corporate stalwarts of the tune of Takaful and Telekom.
A lot has been said about the right and wrong of a Muslim greeting non-Muslims wishing them happiness on their religious/cultural holidays, so i won't go there. Almost nothing has been said about the role of the imam/mufti/cleric in the practice of Islam by a Muslim, and that's the real issue that concerns me.
To put it bluntly, the source of the problem is the reliance of Muslims on these religious "middle-men". These "learned" fellows tell us what is right and wrong, make interpretations for us, and, largely, we bow our heads to them and follow them like sheep. A typical Malaysian Muslim's religious teaching is very similar to the rote learning our youth is subjected to: do not question. Listen and accept. As children, that is our introduction to religion and the religious authority of "learned" Muslims; as adults, very little changes.
The hallowed ranks of the imams have spent many a year studying the religion, memorizing the Quran, can speak perfect Mecca Arabic -- therefore they must be right, we are ignorant in comparison and since we all want to be good Muslims, their word is sacrosant.
In Malaysia, we have large governmental organizations like JAIS, JAKIM, etc. making macro religious decisions for us. In our local mosques (and we tend to frequent the same mosques every week for the sake of convenience), micro religious decisions are made for us in the guise of sermons, prayer groups and neighbourhood councils.
We have ranks and ranks of imams/muftis/"learned" scholars between us and Allah -- am i the only one who sees something wrong with this?
One of the reasons why Islam held its appeal to the early Muslims during the time of the Prophet was the fact that it allowed Muslims to speak directly to Allah; this appeal holds true even among new converts to the Islam in modern times. There were no priests or clerics Muslims had to pay a tithe to, or use as a medium to speak or understand God. Everything was in the Quran (written in a language every early Muslim could understand like we undertand English), and things which were not there, or perhaps unclear, Muslims were trusted on to make their own decisions. If you made a mistake, then God would punish you in the Hereafter, if you made the right decision, then you would be rewarded. On the balance of probability, a "good" Muslim with good intentions would probably do more deserving reward than punishment during his lifetime.
Very simple, straightforward rules. All of which have been blurred with the legions of "mediums" every Muslim is now faced with in modern times, most of whom are there for the holier-than-thou reason of being our "spiritual-religious guide". Muslims are no longer trusted to make our own decisions (and bear responsibility for the religious consequences) -- we are now "blessed" with individuals who know more than we do who can tell us what to do, what to think, what to say.
Let us not underestimate the power these individuals have over our lives, because it is indeed considerable. The fact that they tell us what we can say or do with our fellow man, who happens to be celebrating an event not of the Muslim faith is truly the least of our worries. The events at Takaful and Telekom were caught and highlighted -- high-profile situations brought to the attention of the people. But how many imams saying the same thing in small local suraus and mosques across the country have gone undetected, their congregation, many of whom may lack the critical sophistication of Muslims living in the big cities, hanging on their every word?
I am a Muslim and i will lead my life the way i see fit, with God and His Holy Book and His Messenger and my own religious conscience as my guide. The interpretations of their words and their intentions will be my own. Perhaps i'll make many mistakes along the way, and do things that i shouldn't, but that's a matter between me and Him when the time comes for me to account for my deeds. I'll be damned if i let someone else get between me and my God.
In a perfect world, Islam (and Muslims) would be better served if "learned" Muslims and religious institutions helped us with the skills required to be better Muslims rather than make religious decisions for us. Facilitating easy access to authenticated materials of the hadith and the Quran, classes to teach us Arabic so that we can read the original texts and come to our own conclusions, advisors and councillors who advise and recommend rather than dictate and punish.
Postscript: Islam is the world's fastest growing religion. It has been for the last 2 decades now. But if you compare the conversion rate to Islam in Malaysia to that of developed nations such as the USA or UK, you will find a huge difference. Think for a moment and ponder why this is true. If you've read this far to read this postscript, you already know the answer.