And Amway, too. 
Seriously, I’ve been to Grand Rapids, and it’s the antithesis of Detroit. Sure, it leans politically conservative, but it’s one of the cleanest cities I’ve ever been to, it’s safe, it has a vibrant downtown with a halfway decent nightlife, a growing population of young professionals, and a damn fine microbrewery. It struck me as kind of a smaller version of Minneapolis.
The downtown, in particular, has gone through a really nice revitalization over the past, I dunno, seven or so years, and improved public transportation across the city would be really nice.
The environment, for one thing. Every additional bus passenger means one less car on the road, which means reduced particulate and greenhouse gas emissions.
Traffic, for another- each of those bus passengers is a car you aren’t stuck behind.
Thirdly, efficient public transport increases labor mobility, which means reduced unemployment.
There’s a common canard that no transit service ever broke even. The same could be said for highways.
You subsidize others’ transportation for the same reason you subsidize food stamps, public housing, health care, social security, etc. It’s part of society that helps people drag themselves out of poverty. Also, not everyone can drive a car, even if they could afford to do so.
Let’s take a moment to imagine a world where all urban travel is done by mass transit or self-propulsion. Traffic deaths would be almost nil. Less pollution, which also reduces deaths and improves quality of life (this is one point that gets overlooked a lot- air quality kills thousands of people a year). So, if you don’t like paying for someone else’s transportation, you might as well be a hermit.
And yes, GR is a lot different than Detroit. If it weren’t for the west side of the state, Michigan would be eastern Europe, circa 1992.