How many Python programmers are there in the world?

Maybe. Certainly, if you need precise figures it's not worth much. But if you want an order of magnitude then it might not be too far off. Given that three largely independent measures got to vaguely similar numbers, I'm now pretty comfortable that there must be between 1m and 5m Python developers, which was all I needed for my own purposes.

To stretch your metaphor to breaking point, pissing in the wind at least tells you roughly how strong the wind is (did it end up on my shoes, legs, or head?) and which direction it's blowing.