I would have preferred metric. I spent a minute trying to figure out how the distance a pitched (US) football could be a useful unit of measure when it's so variable. Then I realized pitch means field. And probably not a US football field.

US football and football/soccer fields/pitches are about the same length (~100m)

It's just a ballpark figure...

I also don't like using "football pitches" as an unit of size[0], but unfortunately you and me are not the target audience of this comparison.

> I guess around the world it's assumed that the reader has intimate familiarity with lining up sporting fields

Because it's probably true for the great majority of the population.

[0] - I've been to a real football pitch maybe 3 - 4 times in my life (for non-sports related events), I don't usually watch football and I don't plan on starting to do it. I'd much prefer for sizes to be measured in multiples of Space Shuttle wingspan, but I guess it won't fly with 99.9% of people ;).

It's nothing to do with the metric system. Can you visualise 330m, or would it be easier to visualise three football pitches (or insert any other familiar large area)?

Metric system quite intimately. I measure all my travels, all lengths of anything meaningful, just about everything with these units. I know how long it would take me to bike, walk or drive that.

I know how much that would cost me in server farm, apartment, and retail space. My exposure to a magnitude (or a collection of) meters far exceeds my exposure to a large area reserved for multiple say, soccer fields, or any intuition on really how large they are.

To be honest, whenever I hear something like "17 football fields" I go look up the distance of a football field to try to understand what the heck they are talking about. They might as well have phrased it as the distance a snail travels in the time it takes for a tea-candle to burn.

I use metric and imperial units every day. I intuitively and immediately know what 330 meters is in almost any context.

Very large sizes are often described in terms of football fields. Or basketball fields, if they're smaller. There's something reassuring and familiar in such comparisons which rings better for many people than (400 by 100 meters). While I come from a metric country, I can imagine why a football field comparison sometimes gives a quicker sense of scale.