I was browsing the J. Crew website yesterday and was surprised to see the half tuck has risen. Maybe it never completely disappeared, but I thought the half tuck went the way of white flops, which Stylish Young Co-worker and Rock the Silver readers voted uncool in August of 2009. I'm still proud of my rebuttal to SYC.
Perhaps you will be surprised to learn that I am a fan of the half tuck. I never gave it up, even when the pressure to tuck or untuck was intense. The half tuck showcases a cool belt and a reasonably flat stomach. The sides and back are free-flowing to cover any muffin-like bits that are trying to escape. I would not sport this style for work, where it would come across as sloppy. However, I most certainly wear my weekend tees in some semblence of a half tuck.
That said, I suspect half tucks are somewhat controversial as a fashion statement. Break it to me gently.