Statement: All the player characters have loss and defeat as part of their character arc. If they didn't, they'd be quite boring. A story of constant victory at no cost is hardly a story worth experiencing, is it?
Analysis: Each protagonist the Masters make has both loss and defeat, as well as gains and victories. Let's go through them and see if the gains outweigh the loss, starting with KOTOR's Revan, who met my ancestral prototype.
Revan:
Loses: Previous life's memories as well as new life's innocence after the revelation of their former identity.
Defeats: Taris, Dantooine
Gains: Power or redemption.
Victory: Star Forge is destroyed or gained, either saving or condemning the galaxy.
The Warden:
Loses: Previous life before the Wardens, possibly their new life as well.
Defeats: Ostagar, Lothering
Gains: Fame and (possibly)fortune combined with a life of duty.
Victory: Archdemon is defeated, Fifth Blight is ended, Ferelden is saved.
Hawke:
Loses: Most or all of his/her family, then their new life in Kirkwall
Defeats: Lothering, the loss of their siblings and mother
Gains: Riches, fame, possibly power
Victory: Mage anarchy/freedom or templar tyranny/order.
Shepard:
Loses: His/Her life(control/synthesis) or health(Destroy).
Defeats: Kaidan/Ashley, Horizon, Earth Invasion, Thessia
Gains: If alive, enough royalties from the vids never to need to work again. Maybe a promotion.
Victory: Reapers constant wiping out of all life in the galaxy is ended
Inquisitor:
Loses: An arm, possibly the majority of the Inquisitions infiltrated powerbase.
Defeats: Haven
Gains: Fortune, fame and power. A LOT of it.
Victory: Corypheus defeated, the Breach destroyed, Thedas saved.
Opinion: The loss of an arm seems fairly minor, by comparison. The Inquisitor seems to have lost very little and gained quite a bit.