I never sign any letter of this kind. … If you sign one them, it becomes harder to say no to [others] … I didn’t think the letter went far enough. It attempts to draw a sharp distinction between prediction markets created by academics for research and other kinds of markets. A subtle implication of that distinction is that the government has some legitimate role in restricting access to prediction/gambling markets more generally.
Signing a statement in favor of legalizing A, when both A and B are now illegal, does not mean that one favors keeping B illegal. Not every statement can or should address every issue.
Fear of meta-signals clearly adds noise to such signals. Perhaps we need a website full of statements which we can each browse at our leisure to choose the ones we will publicly endorse or oppose.