I don't think the argument "If its unsafe for the plane, it is unsafe for anywhere else" is compelling.

First, there are all sorts of things that are believed not to be appropriate for a carry-on bag, yet are considered reasonable outside the sterile area (e.g. a box-cutter).

Additionally, and perhaps more to the point, the liquids rule is supposed to keep terrorists from attempting to get hazardous materials on the plane (admittedly this presumes a level of effectiveness that doesn't appear to be exist). If the terrorists believe that there is no way to get their dangerous liquid on the plane, there is no reason that they would bring it to the checkpoint to get confiscated.

Obviously they might be using the TSA as unwitting dupes to get their radioactive/biohazard shampoo to homeless people, but there would seem to be much more direct ways of introducing dangerous substances to consumers (e.g. just return tampered product to a store).

Finally, both sides of the binary explosive debate befuddle me.

On one hand we have the TSA that behaves like a prepubescent saying "Oh there is a threat, but its a secret and we wont tell you. . .nyah, nyah" and can't produce anything that exhibits critical thinking or intellectual honesty.

In the other corner, we have the TSA attackers who point out that it would be impractical to rely on TATP or similar and ignores other more reasonable threats such as nitroglycerin.

Incidentally the 3-1-1 nonsense does nothing that I can see to inhibit mixing up a batch of nitroglycerin. So we are left with the worst of both worlds: A costly and annoying security process and no mitigation to a real threat.