Who gets to say that the demos is fundamentally flawed? Each in-group have their own opinions on what's a flaw.

Society evolves through epiphenomena caused by the behaviour of the majority; the fact that some minorities view that evolution as 'flawed' cannot change that evolution, unless they're able to influence the majority to also see it that way.

Now, democracy is essentially a way for everybody to broadcast their views on society's flaws on non-violent ways. The alternative is that some groups broadcast their opinions in violent ways, and we have learned to see that situation as undesirable.