Color blocked garments are really in right now. Whether it's the myriad of Euro patterns or the catalogue from DBD (or other fantastic designers like Elliedactyl), they are wonderful for using scraps, making good use of coordinates, and they're just plain fun.
The downside is, of course, that the nature of colorblocking means many seams on the inside of the shirt.
For many people, this is a deal breaker. Whether it's an issue of sensory aversion, sensitive skin, or just plain preference.