My belief of the theory has always been to do with
the efficiency of the wheel brakes i.e to get the weight
of the aircraft on the wheels asap (hence spoilers)
If the runway is wet, a greaser will not deliver the
true weight of the a/c but an apparant weight significantly
less which in turn will cause the wheels to lock-up and
engage the anti-skid system which will, due to less
braking efficiency will increase the landing roll.
If Im completely wrong..so be it!
