That actually seems fairly reasonable to me. If there's something causing daily pain to me or someone in my family, I'm much more likely to spend time, attention, and money on that than on something that is another city's responsibility and is not affecting me directly.
This is a natural and beneficial form of decentralization. I don't expect you to be concerned that my grandmother broke her hip. It's properly a big deal to my family, but not even a blip for yours. I want daily/several times per week updates on her progress; you don't.
We all have a finite amount of time, attention, and money, and while I probably know more about the origin of the Flint water situation than the average American (owing to the latter being near zero rather than deep expertise on my part), I'll be honest that I'm more worried about the water quality in Cambridge, MA and in the schools my kids attend.
There are millions of unfortunate or even tragic events unfolding in the world in any given week. It's unreasonable to assume that everyone should care about all of them or judge the situation to be "of course horrible" when we don't. We'd get nothing done as a society if we stopped to mourn every tragedy everywhere or to get weekly updates on years-long remediation efforts.
I sincerely hope that the city of Flint is able to address the entirely city-inflicted (though funding related) water quality issues for its residents. If they aren't able to do it alone, I hope they ask for and get help from the encompassing county, state, or feds.
At the same time, I conclude that there's nothing with a productive return-on-time that I should be doing, because people who are far more informed, more educated on water treatment specifics, have devoted >100 times the amount of time as I have to understanding the issue, and are in a position (spatially and with authority) to make productive decisions are working on the problem.