Gee - good question. I don't know that I can answer that since I have done a variety of patterns and a variety of colors. Some of the color combinations are not my style and are quite challenging. Now if I only worked in colors/values I liked, they might start looking alike.
I find that joining swaps (where the partner's preference is stated) is a good and easy way to branch out. Another way is to take classes and try something new.
.....however, if the quilts are well done and pretty - does it matter if they fit in the same family?