Hey this isn't an argument man, chill
This is you presenting your opinion and your DM's opinion and now us forum lot are offering opinions, debate is a much more relevent word.
its been said by a poster before it does look like your trying to use this forum to prove your DM wrong, I don't think its going to work, it sounds like your DM explained how the force and dark side points worked at the start, but now after playing a bit feels like it would be better for the game if dark side points were easier to get.
If your going to try and get your point across explain how this ruling on dark side points would make the game worse for the entire group not just yourself, including non force users in the group who may be getting overshadowed by the jedi.
Having said that I think Luke was pretty much a grey jedi not light side or dark, after blowing up the death star, killing the dark lords of the sith very good! killing thousands of innocents not so good.