From an editorial in the NYT by Nick Kristoff, Jan 2005:

I called the World Wildlife Fund, thinking I would get a fight. But Richard Liroff, its expert on toxins, said he could accept the use of DDT when necessary in anti-malaria programs.

"South Africa was right to use DDT," he said. "If the alternatives to DDT aren't working, as they weren't in South Africa, geez, you've got to use it. In South Africa it prevented tens of thousands of malaria cases and saved lots of lives."

At Greenpeace, Rick Hind noted reasons to be wary of DDT, but added: "If there's nothing else and it's going to save lives, we're all for it. Nobody's dogmatic about it."

To see what Rachel Carson actually said about DDT in Silent Spring, go here. Basically she's pointing out the problem of resistance - the more you spray DDT or any chemical pesticide, the more the insects develop a resistance and the less effective it is. With that knowledge, and the knowledge of what it does to the natural world and maybe to humans, it would be foolish to use DDT too much. She says:

"No responsible person contends that insect-borne disease should be ignored. The question that has now urgently presented itself is whether it is either wise or responsible to attack the problem by methods that are rapidly making it worse."

You might also look here for more information about what the World Wildlife Fund recommended in the 1990's.

I'm sure there were differing opinions. Environmental groups have a spectrum of different operational frameworks. But I don't think any major enviro group would advocate a ban on any technology that could save millions of lives. They might caution about the need for more research and caution in using the technology, and they might present alternatives that would actually work better.