Shell Rotella T6 5w40 in my 2012. Yep, the stuff may be sold as diesel oil but it also makes a great motorcycle oil. It's full synthetic and FAR cheaper than Honda's synthetic HP4. It costs about the same as GN4. GN4 is standard non-synthetic, but still a quality oil.
I use 5w40 because it's hot where I live and Honda recommends running 40 weight in the last gen bike during hot weather. They don't mention anything like that about the NSC, just 10w30 in all weather. AFAIK, you can get Rotella T6 (full-syn) in 5w30 and Rotella T5 (syn-blend) in 10w30. edit: I don't think the either of these meet MA specs. Odd. Check the labels!
Don't stress about the first number, it's not important like the last number. If you find the oil you want in 5w30, run it. Just make sure is says it meets JASO MA standard on the bottle and does NOT say energy conserving in the bottom of the API donut or you might have clutch issues.
There is no such thing as motorcycle oil, diesel oil, car oil, lawnmower oil, etc. Different oils are MARKETED for different purposes, sure, but don't get hung up on labels and hype designed to empty your wallet. You can run whatever oil you want so long as it meets the specs required by the engine manufacturer.