On the topic of vertical video

ACraigL thought this was worth mentioning said
3

Just reading the Mehmail for the day, and Irk brought up (my shared) annoyance at video shot in vertical smartphone format. But here’s the thing… why is that even a thing?

If I try to playback a landscape (or “normal” or “correct” or “intended aspect ratio”) video while holding my smartphone vertically, I get a really small landscape video that is heavily letter-boxed. However, if I shoot video that way, I get vertical video. Why does it not, by default, either crop to the correct format, or record sideways, therefore prompting the user visually to turn the phone?

MiBMMTiS?