So, Bitcoin motivates behavior of stealing computing power from innocent computer owners.
Sure, in exactly the same way the existence of credit cards motivates behavior of stealing credit card numbers from innocent credit card users.Or the existence of bank accounts motivates hackers to try to break into your system to find out your bank account number.
Or the existence of cars motivates some people to steal gasoline from innocent service station owners.
I believe the benefits of Bitcoin will outweigh the harm, and I further believe that I am capable of making that moral judgment. I might be wrong, and I might regret I ever got involved, but if I only ever did things that I was 100% certain were going to work out for the best I would never accomplish anything new and interesting.