Many purely academic studies are done with predefined strategic objectives of advancing one's own prestige, only publishing positive results that fit "your narrative", and indeed polluting the literature with results that are at best incremental improvements, at worst regressions made up to look like improvements.
(if not then ignore the question - I'm just curious about the mindset of people who do ethically-questionable work)
That won't help. All research is subject to the bias of the researchers. For example, many researchers have been caught fabricating results so they'll get famous. And just because someone is being funded by the government hardly means the government doesn't have a biased interest in the result. Everyone running the government has an agenda that isn't exactly altruistic.
Just a while back there was an article posted about how studies SHOULD start out with defined objectives. The argument was that academics are so desperate to publish positive results that they'll draw any positive conclusion, even if it wasn't what the study started out trying to accomplish.