Designers tend to be on the other end of this spectrum - illogical and problematic. Seriously, we tend to be the sort of people who get excited about an idea and (often) don't think of the consequences or impact such an idea might have right away. At least, I will admit I can do that sometimes. Luckily, we have engineers to poke holes in every system or feature we ask for. While this process can sometimes be trying, it is a completely necessary part of game development.