Let me start by saying that I have read many forum topics on this subject and am aware that there are other related threads. I wasn't able to find a good argument for the inclusion of combat experience however, simply many people trying to defend this design decision. I was an avid fan of the Baldur's Gate series and for this reason I must express my disdain at this decision as I believe it will remove the way that I enjoyed playing Baldur's Gate.
In BG I and II, experience can be earned through killing monsters and NPCs. This means you can venture to areas which are of a high level of difficulty and earn a high level of reward, solely for your ability to kill mobs of monsters. This required searching for canny strategies (Basilisks in BG I for example with scrolls of immunity to petrification) and encouraged players to try out a diverse set of characters, spells and skill combinations. Of course, this does not mean that you must skip the storyline, it simply means that you can challenge yourself _for a reason_ other than following a particular quest line.
This particular feature encouraged me to solo the game in BG I and II once I had completed it following the storyline. The reason why this topic has been so hotly debated in my opinion is, aside from the fact that it is a major change from the original Baldurs Gate series is that removing this element from the game removes one of the basic ways of playing the game.
Wasteland 2 goes a step further in depth in the sense that not only do mobs earn experience but killing NPCs earns you experience and changes the plot line. It is much harder of course to implement a game which allows for this level of freedom. In Baldur's Gate this was never the case. You could kill Shandalar, Drizzt or Elminster without dire repercussions. It did however take ingenuity to do it.
Having played PoE, the first thing I did was to launch all of my party members except my main character into combat with the poor folk over at Dryford. It took a long time but I successfully managed to rid myself of the NPCs by killing them. Then I proceeded, with my solo monk, to explore the surrounding areas and to follow the main plotline. Without earning experience from combat however, it all felt rather pointless.
My question is this: Will PoE genuinely not have experience earned through killing mobs upon release (I have not seen developer feedback on the matter)? And if this is the case, how are you planning on catering for those of us who thoroughly enjoyed playing the original BG series in this way?