Patch 3 was supposed to add more experience and/or opportunities for equivalent exp, and that patch came out in December, some time after the last post of that thread.
The road less travelled is now rewarding...
Our games have always been about rewarding creativity and exploration, but some people were disappointed with the lack of experience rewards for pacifism, and creative solutions that utilize the road less travelled. Patch 3 introduces rewards for avoiding combat situations, whether in dialogue or through exploration and environmental puzzle solving. Now, all you pacifists will be able to carve out a journey more true to your character’s identity. Or, it’ll just offer more options for specific circumstances.
I kinda just took the games word for it - especially since right now we're capped at level 4. It would be interesting to see how much exp you get from different routes.