I'm not sure why you think a "moral obligation to a profession or society" is any more of a restraint on bad behavior than "professional ethics." Or any less of one. Businessmen, from my experience, do not normally put lying on their resumes.

Scientists are not gods any more than businessmen are, and some of them claw for reputation, positions, or grants just as hard as some businessmen claw for a buck. You want to see a jungle, try some parts of academia sometime.

It's professional suicide right now for a climate scientist, or any scientist, to come out on the "wrong" side of this issue, and idiots who claim it's okay because these poor saps don't actually lose their jobs can't change that fact. This is not an insignificant source of pressure.

This isn't resulting in lots of false data, but it sure is an incentive to lean in a particular direction when interpreting it. I can see this every day on websites, with a lot of things boiling down to "well, yes, the data isn't following the predictions, BUT..."