All people do have the right to life, liberty, and property. Just because it isn't fully realized everywhere doesn't mean the rights do not exist. The exercise of rights can be infringed upon by outside force, it happens more often than it should. People can be dicks, it's why anarchy doesn't work as a viable form of "government". But the use of force doesn't negate the right, the right exists and it's important to stress that point. People are justified in their rise against treason and tyranny because they have the right to secure for themselves a form of government which will abide by their innate and inalienable rights.
The idea of natural rights is corner to libertarian philosophy. While many parties can have varying aspects and room for debate; there are cornerstones to the philosophy itself. And if you don't heed the cornerstone, you can hardly be called a practitioner of the philosophy. I've see a rise of poser libertarians lately, those who are essentially Republican but either don't want to admit it or are slightly dissatisfied with the current incarnation of the GOP. They aren't real libertarians because they don't understand our fundamental political philosophy and platform. They like to call themselves libertarian, but have done no research into our goals, our ideals, and our convictions.