I strongly believe that the box office draw is representative of the quality of the use of special effects in a movie, although sometimes the story may be lacking. Such movies that have used this technology well are the Star Trek movies in addition to Alien and Star Wars movies. The list is longer.
In comparison, when I look at the Sci-Fi channel, its obvious to me that the quality of special effects does demand a certain degree of digital artistry. There have been a number of insulting films out there that make it excruciatingly apparent that the use of special effects can be overdone as well as underdone. George Lucas has been innovative in the use of these new tools. I didnt realize how many movies used Industrial Light and Magic for their special effects until a few years back. I remember during an interview with Robert Rodriguez he said that he was strictly a film person until he visited Skywalker studios. After seeing what George had to say and what he had shown him, he said he will never go back to film and shortly thereafter bought a couple of Sony CineAlta HD cameras that he used to shoot Spy Kids.
On the other hand, long time Lucas close friend, Steven Spielberg, has not been swayed by Lucass praise of the technology. As a side note, I think that all motion pictures rely on commerce for their existence. Since motion pictures are an industry, movies are products that are produced then bought and sold on the market, no matter what their quality is.