What is a district, why is it so hard to repair?

[Boris Gudenuf]

I have definitely complained more than once that it either needs to be removed or made super restricted to either 1) conquered cities or 2) cities with loyalty/amenity issues. Not random modern armors popping up in my most loyal, happy, and developed core cities. Luckily it happens less than it used to.

Actually, this might be a way to address another annoyance in the game: make Partisan Recruitment more likely or even automatic Partisan Spawn a feature of 'conquered' City States. If you or the AI insist on gobbling up City States like candy, you should have a good chance of choking on them . . .

 

[Horizons]

This makes scuppering space race projects with spies a very viable strategy in the late game.

 

[Victoria]

This makes scuppering space race projects with spies a very viable strategy in the late game.

Agreed, the issue is that disasters affect the districts which can damage you significantly around T50-100, especially coastal cities that lose all their production.
Making districts repair faster clearly is not a good solution because of what you said and other reasons. Some good suggestions have been made, for example stopping disasters from affecting districts (a simple xml change). Firaxis say they have it in hand.