But the point is that when emergency situations arise, it is NOT guaranteed that you will be able to threshold-brake. Instincts take over, "stop as fast as possible", and you will grab that brake lever with all you've got.
With enough practice threshold braking IS instinct. That's why we practice. A rookie WILL grab the front brake for all he's worth, HOPEFULLY a well practiced rider will not.
To the original question; ABS brakes are a god send to new riders. New riders have more than enough on their plate trying to stay alive while learning how to ride. ABS makes a new rider 95% as good on the brakes as a well seasoned rider(actually my years of local club racing tells me the vast majority of riders have NO CLUE on braking. I am a mid pack rider BUT I out brake most racers). So a new rider doesn't have to know what threshold braking means, the bike does it for him.
The problem with ABS, and traction control and stability control, and the like, is when riders/drivers start to rely on them... and studies have shown that is already the case. ABS has brought us fewer collisions, but the collisions we still get have gone up in price, and injuries.
A rider that can brake at threshold consistently will stop in a shorter distance than any rider on an ABS equipped bike. There is no discussion about it, that is a fact. If you know how ABS works, you know that is true.
The issue IS that VERY few riders can do that, maybe 1%... so that means ABS will benefit 99% of riders/drivers.
I have never owned a bike with ABS, don't want a bike with ABS... and I tucked the front end and went down twice this year... still don't want ABS.
...but I did get to ride a BMW with out riggers. It was at Shannonville in the '90s. BMW had a "press" release of the NEW ABS system. You were supposed to ride the bike with out riggers, slide around, then get on the bike with ABS and stop with confidence. Me and Pedzi were just trying to flip the bike with out riggers. We were having a GREAT time. They asked us to leave.