I will begin by saying that I am not here to bash Witnesses. I strongly believe that the organization provides, for some, a certain type of spiritual need. This would go for just about any organized group or system of beliefs. I think it was a Franciscan monk who said that if we could understand God, then he wouldn't be God. So he appears in different forms.
People have different reasons for going to a church or practicing a religion.
Some people don't feel they have the intellect or the confidence to approach God without some mediator. Some like the beauty of ceremony that a church can provide. Some like the feeling of community. Others need to be told how to think and what to believe. And all this and more is in part, what organized religions provide.