I honestly don't mean to be rude when I say this, but GT Planet's house rules forbid intentional multi-posting, please use the Edit button when you want to add more to your last post. If no one is replying to the thread they won't start replying because you keep bumping it, it'll just annoy people (including moderators and admins).
However, I'd love to see a motorbike sim of the same sort of quality as an established sim like rFactor, but the fact is the hardware you need for it to be a sim rather than a game would be prohibitively expensive and cumbersome for a lot of people. As it is, you can pick up a racing wheel for under £100, under £30 if you don't mind second-hand gear, clamp it to an old table which has been 'reconfigured' with a hacksaw and some glue and do some simulated four wheel driving with feedback, 900 degrees of steering travel and pedals. For the equivalent on two wheels you need an entire self-righting motorbike chassis with tilt AND steering sensors, possibly hydraulics (if you want the same sort of feedback the basic Logitech wheels create with cheap 12V motors) and all sorts of sensors for the throttle, brakes, clutch and shifter, though the last two aren't essential I suppose. Then there's the fact that one design of bike chassis will limit the types of bike you can simulate realistically; if you have a sport bike chassis it will feel really odd when you 'ride' a tourer, like playing Euro Truck Simulator in a home made F1-style racing cockpit! I'm not 100% but I'm quite sure that would be too expensive for a lot of people, especially when no software to support such a system currently exists... And it won't exist until the hardware does, so it's a vicious cycle.