Simplicity is better than complexity.

Simplicity is better than complexity.

But a major point of Wheeler's argument is that existing programs, filesystems, and indeed operating systems already assume that these restrictions are the case, as a matter of convention, but do not necessarily do anything to ensure that they are enforced. Existing software already rejects or fails to properly handle filenames which would violate these conventions, and the vast majority of existing files are named according to these conventions; at the very least, filenames with leading dashes, tab or newline characters, or shell control characters are very rare, and probably accidental or malicious.

So the entire point is that the changes required to existing software would be minimal, and existing software which could break on filenames that don't obey these restrictions when they're not enforced by the OS, would no longer have a problem.