I don't feel like delegating to a service that rewards users for their delegated SP is a worthy cause. Maybe if you were delegating to a user(s) who constantly upvotes and resteems quality content, it would be more selfless.
Obviously I don't know what you do with the rewards you're given from delegating and yes you deserve some sort of payment for being a witness, but there are better ways of showing your dedication to the community who are keeping this platform going. I don't feel that is a legitimate reason for your case.