It does seem like a lot of fabric, but there are a lot of seams, too. the more seams, the more fabric, which is why the front of the quilt takes so much more than the back. I just designed a queen quilt for DH that is calling for 11 1/2 yards, and that's with a big panel in the middle.
I don't seem to have that particular block in my pattern library, but making one that's very similar I'm only coming up with 9 3/4 yards for the background.
I have heard that EQ figures yardage based on squares & rectangles. So each of those odd-shaped pieces the program draws a vertical line on each side, and a horizontal line on top and bottom. Even those narrow strips get this treatment.
Previous versions were really screwy on figuring yardage. Say you had a 4 inch border on a quilt that measured 45 x60. Long strips were not pieced, and it thought you could only get 1 strip per length of fabric. So it would tell you that you needed 5 1/2 yards to make your border, instead of 5/8 yard that you really needed. I remember once that it told me I needed 35 yards of fabric to make a full sized quilt. Thank goodness it doesn't do *that" anymore!