I think the word 'religious' as used by CS CAN be appropriate when describing non-theistic beliefs.
For example, if people venerate a belief system, use it to define their values, resist criticism of it and changes to it, and criticize or judge others who believe differently, then it's fair to call their attitude 'religious'. Likewise if they treat an individual the same way. So for example, I would include extreme left and right wing politicians and some music fans in this group.
When Richard Dawkins describes atheists as 'brights', ie intellectually superior to the religious, he is entering this territory.
If I'm honest, I would say my own belief in the scientific method is religious. That provides the energy for my discussions with creationists.