> All social sciences are at risk of doing so,

It's like saying that the Titanic was at risk of sinking after it hit the iceberg.

> A trained economist either sells out to the Overlords or he gets a job as a barkeep.

That's what training is for.

> Human intelligence is a remarkable adaptation, but "tendency towards delusion" might be the decidedly maladaptive trait that comes with it.

I'd say the reason is more external than internal - personal interest is a mind bender.