Why are the activities exported?

[mobilekosmos]

Why are both main activities in this library exported=true?

If we override them like so it still works, so what's the point?:

<activity
    android:name="com.google.android.gms.oss.licenses.OssLicensesActivity"
    android:exported="false" />
<activity
    android:name="com.google.android.gms.oss.licenses.OssLicensesMenuActivity"
    android:exported="false" />