A serger can be used to make a quilt, but I personally had problems with both accuracy and seam bulk when I tried it. For me, anyway, it's much better to sew quilts on a sewing machine. The serger is great for sewing curtains and clothing (especially knits), not nearly as useful for making quilts.
There are many quilt patterns that can be made on a sewing machine that cannot be made with a serger. The serger is much more limited for quilting applications.