The Light Side restricts its users from gaining some knowledge/power.
I was always someone who preferred the Light Side over the Dark Side, because the Light Side offered serenity and control over yourself. I'm also addicted to knowledge, but since the code restricts me from actions that will give me knowledge I chose the Dark Side.
Example; the mission on Tython where you have to find out if two padawans are in love, they offer you a crystal if you tell their master they are not.
In my opinion those two padawans have failed their trials and even if I dont stop their training now by telling their master they are in love, I'm sure they will mess up their trial again because they lack what Jedi need.
I know they are doomed anyway, but this crystal of theirs is rare and has some history to it, I must preserve this crystal and its history by protecting it. (This is called Lorekeeping).
By protecting artifacts that may have some valuable research to them, research which may aid people who are in fact worthy of this (The two lovers were not, because they lack control) I create progress.
And progress is essential.