I am curious as to the design decision here.  It seems reasonable that some independents would not be looking for conflict, but the absolute passivity of these seems odd.  They don't care if you trespass, they don't care if you wipe out a stack of their units, they don't even care if you take their city -- their remaining units remain harmless, even if you have a tough battle to take their city and their nearby units would have a good chance against you.

In my opinion, the game would do better with a continuum of independents' hostility, where some are looking to raid and fight as a way of life, some do so occasionally, and some only become hostile if you behave aggressively towards them.

As it is, the ideal play style seems to be to farm them, for militarist stars and then to avoid using influence to place a new city.  And it feels gamey.