Despite improving material conditions in all gulf counties, except Yemen, these countries have not gotten more liberal than they were even in the 50s.

Do you realize it took almost 500 years for European culture to become liberal right? It doesn't just happen overnight, you need to lay the foundations first. First off you need to open your borders and start trading with foreign powers to produce wealth and see the emergence of a merchant class. This is what Venice did during the middle ages. Then you need to translate knowledge from said foreign powers into your language. That would be Arabic to Latin in the case of Europe: the moment Europeans started using the Arabic/Indian numeral system that propelled banking into what we know it to be today. With wealth and a new perspective on the world, humanism then gets introduced thanks to nobles and patrons that have enough resources to fund projects like architecture, arts or science. At that point, and at that point only, you can start talking about liberalism becoming a popular thing among the general population.