Many people act as if the "Sunday obligation" is yet another "unnecessary rule" by the RCC, but the idea predates the [Roman] Catholic Church. Forsaking the Sunday Eucharist without a justifiable reason breaks the third commandment, which both Catholics and Orthodox recognize.
Sunday Obligation isn't wrong, except with how it is worded in the Catholic Church. Why do people need to be threattened with "mortal sin"?
Remember in pagan Rome it was mandatory...an obligation to venerate certain pagan gods. The pagan religion was so ingrained into Roman society. Think of our civic rituals. Their civic rituals were ingrained in paganism. This is one of the reasons early Christians were easy to spot. They wouldn't pray or participate in pagan rituals that were the civic rituals. They wouldn't fulfill the obligatory veneration of the gods. They wouldn't participate in say the rituals that were done before say a race (think of a group of people refusing to participate in the USA or Canadian national anthem before a hockey game).
There is a lot of pre-Christian notions ingrained into Christian worship. Religions borrow from the ones they replace. I just hope our Orthodoxy doesn't incorporate the secularism in today's society. There is a notion to separate home life and church life. This is a hallmark of protestanism and increasingly Catholicism and even more so becoming a part of Orthodoxy.
Things that are deemed "ethnic" are actually ways of integrating the worship of the church into the home life. What's ethnic about north america? The compartmentalization of religion and home life/life outside church.
I think it is hard to grasp that some of our rules are 2000 years old OR older and are hard to interpret into today's secular world. Such is the notion of "obligations on sunday." Again there are major differences in the Western spirituality versus Eastern.
The same result of the obligation on sunday the Catholics teach is the same result that you excommunicate yourself from the Orthodox communion if you miss three Sundays in a row. You have to go to confession to receive commuion; translate into western terms... you are excommunicated and the priest has to re-receive you into the church through confession.
So both sides have rules. It's just how you present them. And in today's individualistic society of "me me me, don't tell me what to do" this notion of a mortal sin to miss mass on Sunday just doesn't sit well with that attitude. Re-adjust it; look come to mass every sunday, if you miss please come to confession.
Also a major difference is that in many of our Orthodox parishes the priest knows everyone. It is hard to approach the chalice when you know you can't and especially since the priest knows where you sit or has told you not to take communion for a period of time.
Whereas in the Catholic churches communion is seen as a right, a personal experience. Not so much in the Greek Catholic parishes.
In the Orthodox church the chalice is what unites us. Believe in the Deposit of Faith and share communion, or Jesus. We are brothers and sisters because we share in the holy gifts. We are taught that if we have a problem with someone in our communion then we don't take communion because it effects the community.
It's hard to rationalize or understand if you have never lived it.
But I know from experience the Roman Catholics teach communion very solidly but they don't ask questions they leave the individual to decide if he wants to commune. Sure I think they do ban some from communion but it is for specific rule violations. It is a more individual experience. And we have seen examples in recent times of priests who have turned down people at the communion rail (so to speak). It didn't fair well for the priest.
So we are talking apples and apples here... one is a granny smith and the other is a red apple. Both are apples just different flavours. Let's not get caught up in all in the language.
Let's face it; Orthodox and Catholics speak sometimes an entirely different language on faith.