Punished for choosing dialogue over combat?

[Rosh+]

I just did the goblin encounter in the ruined village, where they're torturing the deep gnome. I chose the dialogue first, but wasn't satisfied with the amount of EXP I got because I knew I should have gotten more, based on all the enemies. I did it again, but fought this time. After an easy battle, I compared all the EXP amount gained based on my previous total.

XP before dialogue/fight: 1162
XP after dialogue: 1277
XP after fight: 1432

I'd noticed this before but never tested it. Seems as if the game rewards combat a lot more than dialogue checks, which is kind of lame. What's the point of building my character to pass these skill checks if I get punished for using them?