The problem with this whole "dark side is evil" thing is that nothing about the dark side of the Force actually seems evil. The biggest difference between the light side of the Force and the dark side is how they use their space magic, right? Jedi ignore or suppress their emotions, while Sith use anger to fuel their powers. Also, the powers are slightly different: The light side focuses on tricking people by attacking their mind, while the dark side has Force lightning.
So ... why, exactly, is the second one evil?
What you're looking at is essentially a taser.
That's a non-lethal weapon available at any moment. Think about how often Luke could've used Force lightning in Return Of The Jedi to avoid killing people. In that movie, he chucks some of Jabba's mooks into a sarlacc pit while slicing others open with his laser sword. He crushes a cave troll underneath a spiky door. On Endor, he hacks a stormtrooper's speeder bike in half, sending him to an explosive death, and he throws another one into a tree at easily 100-plus miles per hour. All of those deaths could've been avoided if he'd used some of the old blue zappy-zappy. But no, he can't do that, because that's the dark side, even though it would be sparing lives.
And while we do see people on the dark side act evil, it seems crazy to me to blame their evil on the religion they practice, especially considering that the "good" side of the Force does s**t that's just as bad: Anakin abuses his girlfriend, but Obi-Wan mind-controls people into doing what he wants, like Kilgrave (that is, the psychotic rapist from Jessica Jones).