As a personal perspective - perhaps a way of considering this is how we view a word form in English in relation to our personal circles of family and community.
When I think of the word "people" I consider them (the group) from the perspective of "they" - a "common / informal" group of individuals outside of who I am. "People" can be easily associated with those who are a part of my local and personal community.
When I think of other groups such as Society, Government, Commerse, Academia, etc. the words have an increased sense of "detachment or formality" to the group. The words are more abstracted, less intimately associated with who I dentify myself as, and so I am inclined to look at the groups as an "it" rather than a "they".
In other languages like Spanish there are conjugations for these different associative senses of personal intimacy or formality which English has lost.
people (they) are
society, community, commerse, academia (it) is