I pick up that aroma in many beers, if they spend more than about 2 weeks in primary. That's why I prefer a shorter primary, although I've gone longer when I had other things going on.
Leaving in the beer in primary for a longer time is a matter of personal preference- some like the subtle yeast characteristics provided by spending more time on the trub, while others (like me) do not.
I was listening to a Basic Brewing Radio podcast about a year or so ago where they had done an experiment. Three beers, same recipe, but with one with a traditional primary/secondary, one a long primary, and one a short primary only (I think). All of the beers were a bit different. There were preferences among them, as well- and all of them had their proponents (without knowing which was which). It was about evenly divided on which was preferable.
It'd be an interesting experiment for people who have a preference for a long primary (or a short one). Make the same beer, and divide it. Then, pitching the same amount of yeast at the same temperature in each, to keep one in primary 7-10 days and one 3-4 weeks and see which finished beer you prefer. For me, I prefer a shorter primary.