For the most part, because people think of top speed when they think of the hayabusa. So in order to hear about a bike being compared to a hayabusa, -it had better be one of the fastest top speed bikes around.
The zx11 was the former top speed bike from 1990 to 1999. The honda Blackbird 1100xx came out in 1997 and "matched" the zx11 but never topped its highest speed.
The zzr1200 is the evolution of the zx11, -same ergos a little more hp and quicker to 100mph, however the zzr1200 does NOT, top the zx11 in top speed. The zx11 is still aerodynamically superior to the zzr1200, and will still go faster when given enough room to run.
Kawasaki built the zx12r to top the hayabusa in top speed, and we all know that it basically matched it, as well.
The zzr1200 having a lower top speed than kawi's bike of the 90's, is relegated to being a comfy sporty tourer with a hefty powerplant, but nothing above 170mph.
A very excellent bike, - however still carbeurated, and a bit old tech in its design...and heavy.