Reread the thread.

> 'Market failure' is a term of art, and it's generally best to avoid redefining terms of art unless there's a very compelling reason to do so.

The person conflating "market failure" with what they were talking about is the GP.

The original comment was about the market failing to accomplish a goal, which is a perfectly idiomatic usage.

I sort-of agree with you, but I was directly responding to the phrase:

>"... they'll never think a failure to meet society's need is a market failure..."

Fair, I didn't actually read that comment that closely.

I was the one who first used the phrase market failure (wrongly, I gather). But the GP only used the idea that a market failed at something: "a failure of the marketplace", which is what my point still stands on.

If they only meant to talk about "market failures" as such, then they are guilty of pedantry