So in a way, this is akin to a "strongly worded letter"
Any country can join these charters as long as they follow the rules agreed upon. What good would it do if you couldn't send a letter to someone in a country under dictatorship? Or if we stopped eradicating polio because the remaining countries are deemed unworthy?
The UN is not this singular place, where you can get "a vote". That is true of the general assembly, but they presumably had nothing to do with this report.
So if millions of people want the opposite, they would enact it but force of they want it enough.
Alas, that is not true. The government always has a military with weapons far more powerful than the public (and the public in a dictatorship is usually forbidden from owning guns). Furthermore, in a dictatorship there is usually a significant minority that is given money and other privileges to support it. So the government usually can simply crush any rebellion in a very bloody manner.
I'm not sure you could get a majority of US citizens to agree with what their government does in the UN.
What does it matter what a few elites at the top want for "their" country, when millions of their citizens usually want the exact opposite?
I doubt that many citizens in the 15 countries that voted against would agree with their leadership on this matter, for example.