When discussing new web technology (especially XML/HTML formats), I've often encountered a particular sort of argument, which goes something like this:

1. Person A: Tech-X seems to capture the 80%, and XML/HTML documents containing tech-x are simple to write. So let's adopt it instead of tech-y, which tries to get 90+%, but whose XML/HTML documents are hard(er) to write.
2. Person B: But tech-x doesn't hande some particular use-case, and besides which, users aren't going to be authoring this by hand! They'll have a variety of tech-y-producing authoring tools available to them, so the difficulty of writing the tech-y markup is irrelevant. Let's adopt tech-y.

Where does Person B go wrong? They've forgotten that it's turtles all the way down: if the end-users aren't writing the markup, someone else is, namely, the tool developer. Tools don't grow on trees, and technology that makes the markup-writer's life easier (be they end-user or tool-developer) will be more widely adopted than those that make their life more difficult.

This mistake happens often enough that I think it deserves a name: argumentum ad adminiculum — argument to the tool — seems to fit the bill. Help spread the meme!

(What prompted this post? This conversation today in #microformats.)