All we need to do to end piracy or pornography is "no-platform" it, right?
Sunlight is the best disinfectant. Rational or not, it's better for bad ideas (ignoring the even more pernicious question of who decides which ideas are "bad") to be examined than have them fester in dark corners.
Given the choice, many people would rather get something for free rather than pay for it. Rather than simply admitting that there is something at least a little immoral about benefiting from someone else's work without paying for that work, they come up with elaborate rationalizations.
There's a sort of virtue in embracing the intellectual honesty of saying that you took that work because you wanted it and had the means. Call it the Genghis Kahn justification.
Even if the work is completely derivative, someone still put significant effort into compiling and organizing it. And their immorality of taking the work of others doesn't obviously justify the immorality of taking theirs.