feline fanatic

Perfect and accurate description of ditching. OP you have gotten many excellent replies and it all boils down to what you want for your quilt. The notion of "SITD is required" probably stems from show quilts. In the case of show quilts, while ditching is not required, when you get to that caliber of quilting where every detail can make the difference between winning and not winning, a quilt that is SITD will beat out one that is not (assuming the two are competing in the same category). It could be the one point that separates winning or not.
As far as a lone star is concerned, when I made mine I echoed 1/4" from every seam, I did not ditch. The echoing reinforced the fabric and the seams as well as accentuating the LS piecing design. I then did "fancy" quilting in the background fabric. That particular quilt was hand quilted not machine quilted. I have seen many machine quilted LS that are not ditched but done with motifs and designs that accentuated the star. Either continuous curves in every single small diamond that makes up the points of the star or an all over pattern that fills the large diamonds that form the star points, ignoring the piecing within those large diamonds. I have even seen lonestars with an all over quilting design. It all depends on what you are comfortable doing, what you are capable of doing and what look you are going for. Google images of Lone Star quilting designs to get a feel for what others have done and pinpoint exactly what look you are going for with yours.
BTW lone stars are notorious for "volcanoing" up in the center. Quilting will often tame it down so that is another thing to take into consideration.