But it devolves into conspiracy theory once they start claiming there's a massive effort by the scientific establishment to cover up the truth,
Not massive in the sense of a centralized effort, but massive in the sense of a defacto effort by reason of their nature to, as Paul said,
hold the truth in unrighteousness; - Romans 1:18
To borrow conventional terms, Intelligent Design and Meaning are so obvious in the natural sciences, that to deny it is a conscious act of suppression of key details.
This clause, τῶν τὴν ἀλήθειαν ἐν ἀδικία κατεχόντων is differently rendered, “Veritatem injuste detinentes — unjustly detaining the truth,” Turrettin; “Who stifle the truth in unrighteousness,” Chalmers; “Who hinder the truth by unrighteousness,” Stuart; “Who wickedly oppose the truth,” Hodge; “Who confine the truth by unrighteousness,” Macknight
“They rushed headlong,” says Pareus, “into impiety against God and into injustice against one another, not through ignorance, but knowingly, not through weakness, but willfully and maliciously: and this the Apostle expresses by a striking metaphor, taken from tyrants, who, against right and justice, by open violence, oppress the innocent, bind them in chains, and detain them in prison.”
The sense given by Schleusner and some others, “Qui cum veri Dei cognitione pravitatem vitæ conjungunt — who connect with a knowledge of the true God a wicked life,” seems not to comport with the context.
“The truth” means that respecting the being and power of God afterwards specified. — Ed.
ccel.org
Further, we're told by the Apostle that they do it all the time, as many believing scientists testify.