Depends on usage
At one extreme, if you use the bike for short hop journeys regularly, I believe the heating / cooling cycle will introduce condensation moisture into the oil much more readily than longer journeys. This moisture will reduce the effectiveness of the oil.
At the other extreme, if you are doing a lot of performance related activities such as track days, drag racing etc. These put a big strain on the oil and again quickly reduces it's performance.
Either end of the scale, I'd probably change oil quite frequently...Every third track day....Every quarter for short hop use.
Otherwise, stick to the service interval and use a high quality semi synthetic (I use ester based synthetic for track).
Hope that helps.
True, but track days don't pressure the bike at all for normal track guys. Pros are a bit different but not that much, imo.