Why haven't the Palestinians ever built a free and democratic society?

They want their own state which is an understandable demand, but whenever given autonomy in Gaza Strip or the West Bank, rather than build secular tolerant liberal societies based on core values of freedom and democracy, theocratic authoritarian regimes were established.

How can the Palestinians claim to be fighting for freedom when they don't even incorporate basic freedoms in their own societies?

The same problem presents itself in the rest of the Arab world, and for that matter, the Islamic world. What stops the Palestinians from deciding to emerge into the 21st century by building a more libertarian progressive society with what they have?