As you said, the developed nations did the exact same thing (including to less developed ones they also stole resources from), and now they expect the rest of the world not to do the same?
People won't give up on a 'modern' lifestyle or better conditions just because it's bad for the environment. Even less so because a bunch of people living in better conditions say it could be bad for them in the distant future.
The only fix is to figure out how to make renewable energy cheaper and easier than non renewable energy worldwide. So it wins on a financial level rather than a moral feel good one.
But we have a small population and our economy is stable, there are other places where we can not expect to do this.
Now it is all changed. Oh, and by going for coal now, developing nations are going to make their electricity more expensive for the next 40 years than it would be if they went with renewables. Is that smart for economic development. And besides that they are going to be promoting climate changes that will be very damaging, including economically, to their own countries.
In fact, I wouldn't be surprised if the developing countries are buying all these coal plants from China at least partly because the people making the decisions got bribed. From what I understand, that is the norm when it comes to China.