I think Holmes and Moriarty appreciate each other.As Holmes commended in the book,"He is a genius,a philosopher,an abstract thinker".He even said to Waston that,"My horror at his crimes was lost in my admiration at his skill".In the meantime,Moriarty confirmed that his rival was cleverest man he had ever met.As far as I'm concerned,it's a kind of feeling that appears when you find someone who is so similar to you in some ways no one else in this world can give you such a strong resonance.

There is not denying that they are rivals to each other.They have the same level of wisdom and capability,but stand in the different position.Their value and pursuit of life are quite different,too.Just as Watson said,"the most dangerous criminal and the foremost champion of the law of their generation."A war between Holmes and Moriarty is therefore inevitable.

Now it seems that I am right.

But that is a fraud.Maybe Holmes knew it,and he just did not want his friend got stuck in danger.

Holmes has arranged for everything.Because he believed that his friend will agree with him and support him.