Also see this Video by Philip VanDusen
Designers have an anxious relationship with the idea of trends. On one hand, following the crowd feels wrong, after all, isn't creativity doing anything but what everyone else is doing? To this line of thinking, the only value in knowing what's trendy is knowing what you're pushing against. You can't simply do the opposite of a trend, of course. But knowing what the trends are makes it easier to subtly comment on and/or critique them.