If the user tries to open the RomFS when one has not been added, it will
result in a segfault (libctru doesn't verify the RomFS actually is
configured). This avoids that scenario when used in conjunction with
cargo-3ds.
An alternative approach would be to do as libctru does and read the 3dsx
file header, and use that to determine if RomFS is enabled at runtime.
This would require more code, but it would be more accurate and
compatible (wouldn't require a tool like cargo-3ds to ensure the RomFS
is added).
TechiePi