Problem is, development doesn't operate on the level of "files". The incremental currency of developers is changes, not files -- and those changes can be both smaller and larger than files. Would you rather see different indentation/braces in different files so that the changeset you're reviewing is consistent, or rather see different indentation/braces in the changeset so that the files being changed remain internally consistent? And what about refactorings where parts of code are moved between files? Should the copied lines be altered so they match the style of the target file?

Point being, "different indentation in different files" is never a realistic way of talking about code style. One way or another, it's always about different styles in the same code unit.