Lucifer gives hidden knowledge to anyone - whether they have good or bad intentions.|
If you give knowledge to people who use it for evil purposes, then you deserve some of the blame for the bad results. This is what we mean by 'Bad Lucifer'.
However on balance - giving knowledge to everybody will result in more good than bad happening. So we might say that Lucifer is two thirds good and one third bad.
This is why the story says that only one third of the angels followed Lucifer when he 'fell from heaven'.
(Of course in reality the 'Good Lucifer' who is with God, and the 'Bad Lucifer' who is estranged from Him, both exist together in a timeless realm.)