Issue is there is no enticement to do anything evil, Larian wants us to test the evil run, use the tadpole, but everything in the game pushes us to do otherwise. If you are looking at the story from a logical standpoint. The only way you would end up with the Goblins and Minthara is if you act like a murder hobo, which I find not all that fun to roleplay. At the moment I'm in the Wrath of the Righteous Alpha, and within that game you have various ways to roleplay an evil character. Larian seemed to have went for the most basic form of evil, which isn't all that interesting.
I'm glad so many people have noticed this and gave feedback, I recall a stream from one of the writers that they're aware the evil route seems abit too "cartoon evil".
The only reasons you equate joining the goblins as "basic form of evil" is because you have no idea what evil is.
Evil is selfishness.
Evil is a desire for power.
Evil is corrupting others.
Evil is not caring if people die (by your hand or others) to get what you wants.
The only one of these which require using the tadpole would be the "desire for power" and if your Will/Int is high enough you shouldn't even contemplate it.
The rest has multiple applications in various quests in the EA if you actually role-play your character instead of just trying to get the "best" outcome or get all the rewards. Quests don't have to be finished. You don't even have to help the grove/goblins to finish the EA.
