If you are not a liability for you team on the defensive end and you are doing spectacular things on the offense, you can be considered for MVP. Guys likeSteve Nash, Chris Paul and in the past, Magic were average defenders who could make every single teammate of his better and basically run the offense. It alsodid not hurt Magic that he was a very good rebounder, the same is true for Charles Barkley. Also, Larry Bird and some day soon, LeBron James, will get MVPs forbe walking triple doubles, who are the clear cut focal points of their teams.
I would agree that if you are a total sieve on defense, you should not get the MVP because all of your offensive accomplishments are dampened if you are aterrible defensive players. In addition, the only players, who are not great defensive players, I would vote for would be guys who are flat out amazing in atleast two of the folloing three areas: rebounding, scoring and passing. Furthermore I would usually only make that exception for point guards and pointforwards and tweener fours. Centers, true power forwards, classic small forwards and shooting guards and had better be very good defenders to get an MVP votefrom me.