Lowest supported Nim version defaults to the current Nim version
Nimble shipped with Nim 1.0.2 suggests that version as default value for the compiler version:
```requires "nim >= 1.0.2"```

This is too aggressive for the majority of future releases. It should default to x.0.0 or x.y.0  (assuming the current version is x.y.z)

EDIT: The Nim ecosystem still has a high churn rate and breaking changes after many years. Developers should be encouraged to support older version of Nim and other dependencies. Yes, that could require testing for backward compatibility, and most libraries use semver to help picking the right versions.
Of course developers are still free to pick the latest version of Nim (and every other dependency), but that has to be a deliberate choice rather than just accepting a default. 