Not to stir the pot, but I don't believe this to be true.
For any doubters, try it yourself. Go to a parking lot and get up to xxx km/h. Pick a spot to brake with ABS. Measure where the bike stops. Put a marker down.
If your bike is able to, turn ABS off. Repeat the above using threshold braking. Your first attempt might be well past the ABS marker.
But I guarantee, after about 5-10 runs, you *will* beat the ABS marker.
I don't think I'm that skilled, but on any given bike with ABS, I'm confident I can outbrake the computer 10 times out of 10 using threshold braking, in dry *and* wet conditions.
ABS is tuned to be waaaay conservative. A little bit of rubber "scritch" sound on the pavement actually stops you faster than a computer letting off the brakes early to maintain 100% grip.
RyanF9 comes to the same conclusion:
HOWEVER...
^ This. Parking lot is not a panic situation.
You do not have to have high skills to beat ABS. You just have to practice feeling what a skid feels like, and learn how to back off the brakes before that happens. If you always rely on ABS, you never develop that skill. Which I think is a shame. Plus, then you can brag to all your riding buddies that you can beat ABS.
Anyone can beat ABS.
But you have to practice.
ABS is a nice to have for me, but if there was a bike I really liked and wanted and it didn't have ABS, I wouldn't hesitate to buy it. Not a deal-breaker for me.