Having a soft shackle at the end of your line is a great asset. A soft shackle lets you securely attach a line to something without the need for a knot. This means that anyone can connect the line without you needing to check their work for a proper knot.
What could fail with a soft shackle on an eye splice? Easy: someone could drop it overboard!
The best way to make a bullet proof soft shackle is to have it permanently attached to the end of your sheet. Making the soft shackle integral to the sheet itself!