It's a three-star shield so it can't easily be exploited in later depths. It has no continual line which makes it worthless later on unless you're a collector. Even the Shield gives very small boost in health which you think would shine! You're wrong.
So why not give Scarlet Shield a Scarlet "Fortress" to protect allies? This may be useful to new-players or even pros willing to help younger-knights help defend them in their time of need.
/yes