I 100% agree, the Dark Side corrupts. You cannot willingly go back and forth between the light and dark side because that contradicts how the force works in established Canon.

The entire reason that Darth Gravid went insane and died was because he tried to blur the line between the light and the dark

Agreed they’re dumb

I have always agreed with this notion and I’m glad more people are coming around to it.

If wielding both sides provides more power, then the Sith would do it in a heartbeat. And if the dark side has no true consequence and is something safe to wield along the light, then all the Jedi teachings of self discipline and meditation would ultimately be meaningless.

Some people tended to see both sides as “skill trees” to be mastered rather than applications of the same Force. That’s why I think the “Grey Jedi” concept has gained so much popularity: it’s the ultimate power fantasy without consequence.

^I feel like TFU played a role in pushing this power fantasy nonsense imo. Love the game tho

At first, I thought the concept of a Gray Jedi was cool but then I realized that being a Gray Jedi just meant making excuses for using the Dark Side without really being a Sith or Dark Side user.

^^Agreed. The TFU videogame definitely played a role; Galen at the end essentially self-proclaims himself to be a Jedi (quote: “I’ve never been a Jedi before”, implying he is one now) after spending the entire game slaughtering armies in brutal fashion using almost entirely the powers of the dark side and it is important to note that these methods do not change once he declares himself to be a Jedi.

The game itself is very fun and I’ve won it plenty of times. But it’s a case of fun gameplay and the rule of cool coming at the expanse of reflecting the core themes of the Force imo.

^ Eh let's be honest, this whole power fantasy thing came WAY before TFU series. That really started imo with the West End Games SW RPG material, where you could in theory make a pretty busted Force User character, because at the time, Force Users were just Dungeons & Dragons Wizards and were based on just dice rolls. Which I believe this is the start where we get many crazy and powerful Force User characters in the EU.

Then you had the Kotor games where you can also be pretty broken and cheese a lot of fights. Though I guess in a more flashy sense, TFU has it, but that's a no brainer.

^Yeah definitely agree that the Power Fantasy thing with Force users appeared way before TFU. When it comes specifically about the Grey Jedi concept, a special mention goes to Jedi Academy where you can literally choose between Light and Dark Force powers as two skill sets and there is no consequence for using either.

TFU just took all of that to eleven by making essentially a Sith character who fights like one and uses a combination of the most destructive and dark Force abilities (Lightning, Choke, Maelstrom, etc.) even when his alignment presumably no longer reflects that. At least in KotOR you have a penalty for using dark powers as a Light aligned character and vice versa.

I've always felt strongly against the Grey Jedi concept even all the way back in 2007 when it was in vogue and I felt alone in my opinion. So it has been a tremendous relief to see that the tide has turned against the trend now. That being said, I do disagree with some of your remarks here about the origins of the concept. I don't think either The Force Unleashed or Star Wars: Knights of the Old Republic are to blame. TFU's entire premise is to be a power fantasy, but it doesn't actively try to promote the Grey Jedi concept. At most, it incidentally does through its gameplay and narrative design. KotOR makes a binary distinction between light and dark side powers, and characters are penalized for attempting to use the powers that do not match their alignment.

KotOR and KotOR II do, however, promote alternative philosophies about the Force and subject Jedi norms and beliefs to fierce scrutiny. The way it most contributed to the concept of the Grey Jedi is via Jolee Bindo, who is evidently a good person opposed to the dark side but is expressly given neutral alignment because he became an outcast of the Jedi Order and defied their oppobrium against romantic love.

This highlights one of the original reasons for the concept's popularity: its conflation of the light side with the Jedi Order. Conformity with Jedi ideological practices was misinterpreted by many fans as the prerequisite for being a light-sider. In part, this probably stemmed from the in-universe pejorative usage of the label to brand unorthodox Jedi like Jolee Bindo and Qui-Gon Jinn, even if they are steadfastly in the light. Fans saw the Jedi and the Sith as polar opposites and, committing the golden mean fallacy and the false dilemma fallacy, argued that they were extremes of equal moral weight such that the most ethical route was actually to be "balanced" between them.

The other reason for its popularity is what you guys have already pointed out: the desire to live the power fantasy. Some fans wanted to be able to use cool dark side powers like Force lightning in their imagination while still reserving the right to be a light-sider. As I said, I don't think this reasoning was promoted by KotOR and TFU. It goes back further to at least Jedi Knight: Jedi Academy, where Kyle Katarn instructs the player that no powers are inherently light or dark and what matters is only how we use them. I always suspected that the writers of this (and related ideas in contemporaneous works) were inserting their distaste for the moral objectivist framework that the dark side's existence implies. As well, they wanted a justification for a more ethical egotist value system to be legitimated in the lore concerning the Force.