I'd have thought that maybe there are some more practical considerations there.

Even I with no knowledge beyond ohms law (and a couple of other snippets) could couple a light dependant resistor to some AD converter on some chip (I do it outside with a solar panel to decide whether mabye pond pump should be running or an outside light at night) although I've no clue what Lux there is - just a simple voltage divider that will give a reading between (almost 0 and 5V). But I wouldn't have the first clue how to illuminate a stadium and give a suitable light for play.