Martin Campbell was actually a very safe choice-- the man has a history of successfully relaunching franchises at the box office, twice with James Bond and once with Zorro. Unfortunately, as people are saying, playing it safe is not going to do DC any favors, and even though I have been looking forward to GL for quite a while I could never escape the feeling that this movie was going to be a "safe" Superhero movie, and it appears that this has affected the movie negatively at least as far as the critics are concerned.
Whether or not the general audience will feel this way is a different story, but I hope that seeing this movie's tomatometer match the color of the lead character's costume has got a lot people at Warner Bros. sweating right now, and that they learn from their mistakes in the future. I was expecting Green Lantern to be more Space Opera than Spider-Man, but hearing it's the other way around is disappointing to hear. Even if this movie is a success financially, Warner Bros. is going to have to re-evaluate their approach to this franchise if and when they move forward with the sequel. If they ever approach another superhero that is not Batman or Superman for an adaptation after this incident (God willing), playing it safe is not going to cut it. Playing all the genre tropes straight will only get you so far if you are not doing anything different from past superhero movies.