It is the Tana Kama who holds what you wrote, Reb Yisroel Alter, in the name of the Chachomim. The Gemara states, near the end of 75a, that when Ravin came, he said in the name of Rabbi Yanai that the Tana Kama holds this, whilst the Chachomim, who are the 3rd shitah in the Mishna; mentioned after Rabbi Akiva; hold that drisas regel ho'asurah bimkoma does not asser.

I think we can compare the svora of the Tana Kama to the dinim of Kashrus. If kosher gravy was spilt on kosher meat everything remains permitted, whilst if treifa gravy was spilt on kosher meat it makes the meat traifa.

Similarly, permitted drisas haregel cannot make anything else ossur, whilst forbidden drisas haregel can make other things ossur.

KOL TUV

Dovid Bloom