Postmodern Beatnik wrote:
If Wikipedia said that, it would be wrong. Now, the word "fallacy" does not appear in the "Support our troops" article

From Wikipedia:
The phrase "for the children", or "think of the children," is an appeal to emotion and can be used to support an irrelevant conclusion (both logical fallacies) when used in an argument.
There are two ways to read this sentence. The first says that the phrase "for the children" is an appeal to emotion when used in an argument and that said appeal can be used to fallaciously support an irrelevant conclusion (or non sequitur). This would be true. The other way to read the sentence is to say that the mere phrase itself is an appeal to emotion and is a fallacy on its own. This would be false. It all depends on what we take the scope of the all-important bolded phrase to be, which should probably be made clearer in the article.

The important thing to note is that there may be perfectly rational uses of the phrases you mention. To take one example: vegans advocate an extreme change in the average American diet, and in that sense they are extremists. So long as we do not allow that fact to distort our analysis of any arguments they may give or conclusions they may draw, and so long as we do not try to use that fact to distort the perceptions of other people, there is no problem.