hello hang-er,
no, i think you are still a bit confused. : a contaminated rwy can be slippery as well & clutter on the rwy can, but is no guarantee for reduced braking distances.
so again keep it simple & fysical(science that is) : a high speed abort= high kinetic energy, you will need a longer distance to stop than an abort at lower speed. on a wet, contaminated &/or slippery rwy, this stopping problem is aggravated & longer stop distances are required, which might exceed the available rwy distance. so, to remain safe, a weight reduction & a speed(V1) reduction is required.
regards,
bm
