I think the article talks about nonviolent protests - the first two were anything but.

The Slovakian incident worked, because Slovakia has a working representative democracy.

In a deeply flawed, or downright nondemocratic system, like Serbia or Georgia, it's very hard to drive change through nonviolent protests.

It also bears mentioning, that the key issue with protesting, is that it, legally speaking does nothing. Legal representatives are under no obligation to do anything in response to protests.

It in itself does nothing, but it is necessary to embolden anyone who can do something.

If nobody protests, people who have the choice to do something will see that nobody gives a shit... And why should they stick their necks out for a cause that nobody gives a shit about?