As a point of fact, I’ve never encountered anybody not understanding “The proof is in the pudding.” The meaning is clear enough. The only complaints tend to be (a) about it being a mis-quoting of Cervantes or (b) a perceived lack of elegance.

And in point of fact, I’ve only seen the whole debate expressed online. In other words, I’ve never heard anyone actually say, “I don’t understand.”

And I’ve never heard anyone use in speech the original phrase: “The proof of the pudding is in the tasting.” It would sound to me a little antiquated. The whole concern appears to be mostly an online grievance, rather than admitting what is used in actual speech.

Linguists have noted that items of language tend over time to move from formality to brevity. I suspect that’s the case here, since the briefer version makes sense (to most of us).

But antiquated to one person might seem more elegant to another?

Or, one man’s brevity is another man’s grunt?
Seem a bit of a jump to call it grunting, but I’ll assume that’s in the heat of a spirited blog comment.

But I’m sure Cervantes appreciates anyone tilting at windmills on his behalf.

You are correct about the phrase being shorter than the original, although without the original’s richness of meaning. Maybe you practical folk in the Midwest should just all grunt and point…save a lot of time that way.

My daughter is an emerging writer, and I’ll definitely point her to your site, with these words of caution, of course: “Abandon all hope, ye who enter here”. (Maybe I could shorted that down a bit to “Stay Away!”.)

By the way, what are you going to do with all those extra words (I counted three) you saved?