"liberal democracy" is an anomaly in history and there's no fundamental reason why countries should tend toward it. also, the "liberal democracies" like your own aren't exactly radiating out peace and love muslims have wildly different in their interpretations of religion and differ wildly in the extent they're willing to practice it, and you see this in the actual practice, regardless of what is said. "shariah" is supposed to be based on the word of god and the words and deeds of the prophet, and as a muslim it would obviously not make sense to directly criticize that because then you wouldn't really be a muslim. you don't usually see christians lambasting jesus, regardless of what they do in practice.
Pirate