funding (or, better, federation's politics to show they're winning medals and therefore they deserve more consideration/funding) is one reason, but we also have a problem to find big men and women to be really competitive in the senior boats.
we still have a lot of guys practicing the sport (but also a high rate of early retirements, compared to other sports, because rowing is truly an amateur discipline, there's no chance to make even reasonable money with it, even if you win the Olympic gold), but our population is basically average sized, so we have a lot of good rowers in the lightweight classes, but we lack people in the senior ranks (and often we use lightweights also in the senior boats).
moreover, the current coaches are obsessed with the Eights and are destroying the pairs and fours to put our best rowers on the main boat (but normally they don't have the same approach and results when they go on the Eight, there's no chemistry among those used to be good in the shorter boats when they are together on the longer one), wasting chances to shine in the other events.