I focus on the demonstrations because they represent some action to change these trends. Just describing them will only depress my audience here.

I suggest Milla is probably the best-organised part of this.

I think Milla is actually less organised, but has a wider pull and is more professional. What I mean is that liking someone on Facebook doesn't amount to much grassroots organisation, or activity apart from attending a protest. (In fact calls on people to organise and do more echoed from the mouth of several speakers.) Szolidaritás in contrast seems to have an actual grass-roots, as do some of the smaller groups like the HaHa students.

The Szolidaritas demonstration last week was a huge failure.

In what sense? If you mean that numbers didn't match Orbán's or even Milla's, then it was, though with the precedents, I feared even less people will turn out. If you mean that there was dissatisfaction with the length and quality of speeches (a sentence in the intro of the Milla protest, "speeches will be short and sharp and voluble", may have been in reaction to that), I wouldn't call it a huge failure.

a kind of gooey unformed mess of different groups, many of whom are contradictory.

Any new mass movement is by necessity a gooey unformed mess of different groups, uniting people who previously only knew the mental frame of reference of a narrower environment. But indeed the question is whether someone manages to get the people to overlook differences and get an idea of unity (even if illusionary), the same way Orbán achieved this. This seems to be the central message of blogger Varánusz, who is also dissatisfied and wants opposition organised in a party. (Then again, he is an LMP partisan, and I'm not sure that we need a single party as conduit of organisation.)

an education system designed in the early 20th century

Actually no. While there are elements that go back that far, the 'communists' implemented significant vertical mobility in their first decade or two (though later their new middle class began to protect their position the same way the prewar ones did) and extended elemental school to eight years, which was then undone in successive reforms after 1990 which made social selection much worse, while also eliminating quality where it existed.

_{*Lunatic*, n.
One whose delusions are out of fashion.}