We tend to associate wheelbase most closely with turning ability; the shorter the wheelbase, the quicker the turn response. If this were the entire story, then Scott Russell's Kawasaki Superbike would be as short as the things that Erik Buell builds. However, wheelbase is also dependent upon tire grip. Back in 1972, Yvon DuHamel practiced at Ontario on an H2R with a 58 inch wheelbase. On the tire then available -- probably a glorified Dunlop 3.50 X 18 Triangular called a 3.50M -- Yvon reported that he was spinning out instead of getting grip to accelerate. Accordingly the wheelbase was shortened by installing a swing-arm three inches shorter. This, by increasing the initial load on the rear tire, allowed the hard old thing to hook up and go.
In 1971 Kel Carruthers had set us all thinking by tsting such things as 350 Yamaha chassis three inches longer than stock, or with the engine set ahead three inches. To the onlooker, the longer chassis looked like the hot tip; when we tried it, it slowed down the handling of those twitchy, pipe-framed horrors and stopped the front ends from pushing off slow corners as tires on short bikes worked to lift the front tires off the pavement. The relocated engine was better because it retained the short wheelbase but defeated the front-end-lifting just as well as did the long wheelbase.
As time has passed, rear tire grip has improved and engine power has risen, so less and less initial load is needed on the rear tire to permit it to grip rather than spin. This same improved grip has made front end push during acceleration a problem that returns every spring with the improved tires that come from the makers. Thus, as before, either the chassis must be made longer or major masses must be moved forward, to keep up with the growth in tire grip. Occasionally this process gets ahead of itself, but the trend remains.
The original race versions of the Honda RC30 seemed optimized for quick turning and acceleration. The development of that bike carried it far from its original ideals; the engine was retuned to bring real power above 10,500, and that power became narrower. Here in the US, the RCs seemed twitchy, resistant to smooth sliding, while Muzzy's Kawasakis, with their lankier build, were manageable while sliding. But maybe it's not that simple. Powerband strongly affects handling now. What we see is a short Honda twitching and sliding unpredictably, while Russell smoothly pulls away. What is an inch or two in almost 60 inches? Back in the 1980-82 period, Muzzy's bikes won races because riders could make them do what they wanted them to. More powerful Hondas ate their tires and overworked their riders. I think this handling business is much more complex than a difference in wheelbase. I think Muzzy takes an integrated approach to motorcycle development, always understanding that performance and handling are different. You can build a machine whose potential performance (for instance, its turning ability) is far better than the competition's, but whose handling (the ability of the actual, human rider to make use of that performance) is, for a variety of possible reasons, quite deficient. Muzzy worked hard back then to iron the 1025 Kawasaki's powerband -- suppressing spikes, filling in valleys -- so that the resulting torque could actually be used by riders and delivered by existing tires. I think he's still doing it.