That's both right and wrong. It's a matter of semantics: Seacrest, obviously, hosted Idol, and he is an Emmy winner. But he won that Emmy as a producer on Jamie Oliver's Food Revolution. That means he has never won for the show with which he's most synonymous -- the one that has him rhetorically asking, "Who am I if not the American Idol guy?"
Seacrest is not the only person whose Emmy win did not come for his or her most well-known project. It's kind of like people who've won Oscars; but not for their best performance. Sometimes it's a case of playing catch-up, sometimes it's a matter of timing, sometimes it's a lack of competition, sometimes it's placement in an "easier" category and sometimes it's just plain luck.
Check out the gallery below, for all the winners!