system
Given the following post, respond as if you're commenting on Reddit:
human
[Skyrim] Why don't more Nords learn the Thu'um?

The Greybeards said that to become a "Tongue" would require a great deal of study and training, and it was not limited to special cases (like the Dragonborn). If people can devote their time to studying Magic, why not in Shouts? 

Special mention to the Nords since they worship Talos 24/7 anyway.
gpt
A: Shouts are a form of magic, while Nords dislike magic.

B: Takes a LONG time to learn even a single one if you're not absorbing dragon souls.

C: Someone has to teach you, dragons won't do that, Ulfric is a busy man, and greybeards will only teach it to you if they chose you as a new greybeard, not so that you can go and shout Imperial army back south.