Patrick Dorinson has an interesting piece on the so-called Western "Watersheds" Project in which he touches on the plastic issue:

...hidden behind the facade of planting trees or discussing the virtues of "paper or plastic" is a well-financed global group of dedicated radicals who are bent on changing the way we live whether we like it or not. They are funded by a vast network of wealthy individuals, trust funds, and foundations who selectively give money to organizations they can control like puppets on a string (think George Soros).

Naturally, plastic is hated by the Watershed people, who are dependably against anything made or done by any humans anywhere, save what they want to do to everyone else, which is of course to make life as expensive and inconvenient as possible and above all tell us what to do. And in the name of protecting "the Watershed," they have appointed themselves as quasi-official agents to inconvenience us and tell us what to do. (And they have lots of money to do it with, too!) Above all, they excel at creating real, brand new power for themselves without ever having to run for office.

"Watershed" is one of those weasel words which activists love to use, for it means very little to most people (it sounds harmless, innocuous, even wholesome and natural), but to them is code language for achieving total control over as much territory and as many people as possible.

If you think about it, there are few to no areas of land on the planet that are not the "watershed" of one body of water or another -- and all land is the "watershed" of the seas.

So what they're doing by using this word is establishing a new system of control. For themselves, of course. Because they care more about "the watershed" than you or I! And they are the ones who should get the power to "protect" "it." (And if you disagree with them, why, that means you must not care about the "watershed"!)

How it is that otherwise reasonable people keep falling for these cheap rhetorical tricks is beyond me.