I haven't logged in here for ages, but, when I saw this conversation--I was compelled to chime in. I am a modern quilter, a member of a modern guild who only seems to be drawn to modern fabrics and construction.
First, I'm not sure anyone has made the distinction between ART quilting and MODERN quilting.
Art quilts are usually smaller, often embellished, irregularly sized/shaped pieces that are decorative in nature.
Modern quilts are made in modern fabrics, using a variety of patterns--often an interpretation of a traditional block. Modern quilts are made to be used, are mostly quilted on home machines, and frankly--there are no rules.
A misconception I want to speak to is: negative space is for fancy quilting? Not so, IMHO. Most modern quilters pride themselves in quilting bed sized quilts on their home machines. The quilting is to hold the layers together and highlight the great fabric choices. Straight lines, SITD, echoing, etc.
As a modern quilter, the biggest difference I can identify between traditional and modern is in color/fabric choices. Our QDO was yesterday, and my modern guild had a booth. I'm not sure it was coincidence that the modern guild booth was dead center in the room, but, in every direction were booths of traditional guilds. While we did display some abstract wall hangings and such (some of the traditional booths had smaller artsy pieces, too), we hung quilts made by our members, and the only significant difference between our booth and the others was color and fabric. The modern quilts read crisper in color and value, while the traditional quilts read more muted. Many of the blocks were repeated in both styles, but translated differently in fabric choices.
As other before me have stated, if it weren't for like-minded younger quilters to help me along this journey--I may not have ever sewed my first seam. The reason I realized I COULD quilt is because of the young bloggers who brought me tutorials online. I certainly have no one in my life who could teach me. So, perhaps my skills are not perfect and my points are a little off. With more practice, those things can resolve. At the end of the day, there are young, bright, creative people trying to keep the art of quilting alive.
As with all parts of our civilization, evolution is part of growth.