I don’t think Venezuela, Libya, or Iran is a fair comparison to Hong Kong regarding the progress or prospect of liberation/democratization. For one, Hong Kongers have been used to elections for almost 30 years now (since 1991), have practiced free press and rule of law, and mostly free of corruption, so I think Taiwan may be a closer comparison in terms of how liberation/democratization of Hong Kong would become.
The recent frustration towards elections in Hong Kong (which is also one root cause of the on-going protests) is that the elections are far from representative or universal suffrage (half of the seats in the Legislative Council–the functional constituencies–have pretty limited representation, while the Chief Executive is elected by a pro-Beijing committee of 1200 out of a population of 7M+), and that some elected members of the Legislative Council who are pro-Hong Kong got outright disqualified. A liberation/democratization of Hong Kong means such issues are fixed, which is more like Taiwan than Venezuela, Libya, or Iran.
That's like saying Germany was a broken state after US intervened in WW2. I mean, it was literally broken up, but it didn't have an insane dictator committing mass scale human rights abuses anymore.
However, the simple fact that the US went in guns blazing and left before things got better (because otherwise it would have been too costly) doesn't invalidate all forms of intervention ever and forever.
It's no wonder such sensitive situations were mishandled. The theoretical magical chain of events that lead to sustained "freedom" was always there, on paper at least, but using the US examples we should conclude that its cost-benefit is waaay way lower than necessary to consider it a useful foreign policy tool.
Of course, an avid idealist might argue that this just means the US (or the world, or the West) just needs more experience to be able to better export "freedom"; and of course it is something we should never stop trying. And even today, even after the whole ISIL/ISIS campaign every place is better off now than it was before. (No Saddam, no Gaddafi, etc.)
Given these examples, Hong Kong would be much better off without such intervention.