Personally I don't have anything against not gaining XP from combat as a concept, but the rest of the gameplay and the area design in the current version of the backer beta does not support the system. I think it needs to be either done considerably better or dropped.
Yesterday I played the game for around 5 hours, exploring all of the town and finished the task regarding the two groups of people, clearing the bandits and climbing after the egg, killing the ogre, exploring the area to the west and most of the dungeon below it... and ended up with a whopping +0 XP for my party. Now granted, some of it was due to my journal reseting towards the end, but that happened only slightly before the ogre cave which was the last thing I did.
I think there are currently too far many unavoidable enemies for a system like this. The HP and resting system are also fairly brutal, more so than in most other RPGs at least, also discouraging combat. I felt like the systems together made combat not just feel unrewarding, but a punishment to the players; a feeling I'd rather not have in an RPG filled with monsters and dungeons. Note that I was playing on Hard difficulty, following the tooltip that said it was a good difficulty for veterans of Infinity Engine games (I didn't find it to be that difficult, but also not rewarding).
If they are to stick with the non-combat XP system, I think they also need to add many diferent sources of XP. Currently it feels like you have to do those few particular things that happen to give XP as soon as possible, then ignore the rest as well as you can. Other potential, more minor sources of XP could be exploration (a big one, simply visiting interesting places), reading books/unlocking new lore and simply talking to NPCs and gaining information that way. It would also be nice if the quests gave smaller amounts of XP more frequently, instead of just once or twice. Additionally combat should be made more rewarding or at least less punishing somehow, perhaps by adding more interesting loot, crafting components don't quite cut it in my opinion.
Note that even though this post may sound negative, I love what I'm seeing so far. Shows a lot of potential. But besides item/journal/spellcasting ability disappearing bugs, in my experience the XP system is what needs rehauling the most currently.