jr,
You are a making a ridiculous assertion. The phrase in Scripture which commands us not to eat with an unrepentant sinner who calls himself a brother is referring to the most basic form of fellowship, that is, sharing a meal together. It cannot be compared with having a meal in close proximity to someone. That is not what the text is inferring. I can eat lunch next to someone without fellowshipping with him. It's quite easy.

If a professing Christian is in sin, the shunning of him from fellowship is designed to bring him to repentance, not to punish him. In a combat situation, there are plenty of guys who "don't get along" and stay away from each other. It's not as difficult as you assert.