Question

Why might institutions of authority tend to reject new ideas developed by scientists and other thinkers

Answer 1

The reason why authorities might reject new scientific discoveries is mainly because these challenge the status quo, and in this status quo they are the ones which hold the power.

For example, this happened with old European absolut monarchies when the era of the Enlighment started. The principles of social contract, suffrage or division of powers developed by Enlightment thinkers were opposite to the religious dogmas that supported the Ancient Regime.