The page that introduced him mentioned that the guy will be antagonizing you and firing at you as you progress through the stage. I thought that was a cool idea; I mean, when there's a robot master who explicitly excels at huge ranges, why would they wait for you to reach a designated small enclosed room before trying to take you down?
I'd even be okay with having his level be excruciatingly hard thank to his constant sniping at you, only for the actual boss fight to be underwhelming because you've finally got him cornered and fighting on your terms.