In general the "Delphi" technique has many many different faces and is almost ubiquitous in all perspectives. To a large extent the practitioners are merely operating from their own bias, rather than intentional deceit.
Delphi is a respected technique in social sciences. Of course, it often gets misused by interested parties, but if the facilitator is really interested to know what "the truth" is, there is no better technique around.
The quality of outcomes can be very high if:
- the facilitator takes care to select a representative panel, i.e. includes experts from both opposed sides
- starts with an almost blank questionnaire ("what are your main thoughts about climate change, in three lines?")
- is very prudent when translating answers to that initial questionnaire into more structured questions (because that is the step where bias can take over)
Again, you can misuse it to confirm your own bias, but if you are really interested to get the most objective synthesis out of the brains of a bunch of distinguished experts, then Delphi is your method of choice.