Because there's a thick layer of white man's guilt in western society. Instead of seeing that those countries are as much a victim of their own decisions, certain people blame anything anyone did to them by dead people. I can't even say 'my people' because my ancestors were as much down trodden as most of those the British affected. They certainly weren't free in any modern form of the word.

There's a certain form of arrogance too, that perpetually assumes the Indians and Chinese need a helping hand any more.

I blame all the introspection into ancestry and history in general.

"How Can China and India be Classed as Developing Countries by the UN?"

Because they haven't yet exported most of their heavy industry to lower cost destinations?

That might seem a slightly flippant answer, but I was thinking about it the other day in the context of China now having higher per capita CO2 emissions than Western economies. The Western economies would have higher emissions today if more domestic heavy industry had remained. So they can be all smug about relatively lower emissions due to a more service-based economy.

Where could China export its heavy industry to as a means of reducing emissions? Effectively nowhere at present, and only to poorer nations in the longer term. This must be obvious to all except the rabid green muppets, and appears another reason why they won't get what they want from developing nations in Paris. Not without huge dollops of cold, hard cash. Developing nations won't sacrifice the opportunity that industrial development presents on the EU/Obama altar. .

I've got no reply to that, Dung, other than to repeat what I said about Tuvalu on "The Perilis of Delegation" thread:

Tuvalu had met targets so that Tuvalu was to graduate from LDC (least developed country) status.

In 2013 Tuvalu deferred its graduation from LDC status to a developing country to 2015.
The reason?
"Once Tuvalu graduates to a developed country [said Prime Minister Enele Sopoaga], it will not be considered for funding assistance for climate change adaptation programmes like NAPA, which only goes to LDCs".

From my limited information, this seems to imply that a country can freely choose when it transitions up the scale.
Maybe countries like Zimbabwe are not allowed to voluntarily transition down the scale.

Politics, power, corruption,and lies, is probably the best suggestion I can make as being the reason.

Developing fighter planes
Developing space programs
Developing a naval air arm

I think that qualifies them admirably.

And both have nuclear weapons, which to me rather overrides any protestation about poor people.

Dung, no question is sufficiently serious or valid that I won't squeeze a joke in given any kind of an opportunity.

Just an observation, both the nations in the original question began their economic miracles by relaxing central planning and control. Each could have been surging since the 1940s had they adopted the economic policies of John Cowperthwaite in Hong Kong. How did socialism help the poor folks?

The term 'underdeveloped', was deemed politically incorrect. The term 'developed', implies wealty, and therefore able to pay money, towards those who are 'developing', who need more money from the developed.

There is no financial or poltical advantage for any country to be seen as developed, and the Key Performance Indicators are therefore VeeDubbed accordingly. Whether money changes hands for sympathetic UN assessments, is, of course, a developing story.

Dung, omitting the countries you mentioned (China, India and Russia) the following countries, ordered by population (current wiki estimates) are next in the list:
Indonesia 257,080,000
Brazil 205,026,000
Pakistan 191,165,000
Nigeria 183,541,000
Bangladesh 159,173,000

United Kingdom 64,800,000 is down in 22nd place

The list of poor nations goes on and on. Those nations and people will not be denied. They are too many to be paid off, even if there was a good case for doing so.

The global warmers gathering in Paris in November have a worse problem than not being able to spot the poor science about CO2 from global warming alarmists: They cannot even do simple arithmetic.

Martin A, you are right, but they are paid to be poor, and once you pay people to be poor you will NEVER run out of poor people. In fact poor people are paying to get to the USA. Which does not run exactly to Cowperthwaitian principles.