Having grown up in that area of the Midwest, I largely agree with the author's categorization, except that "people on their way to somewhere better who got tired and decided this was good enough" describes a LOT of the midwest, not just Indiana. Significant chunks of Michigan, Ohio, and Missouri, most of Iowa/Kansas/Nebraska, etc.
If you read the history of westward expansion, "got tired and decided this was good enough" is literally true for how much of the area got initially settled (by white people)
Spend some time not just driving through them, and one may be surprised to find plenty of diverse and interesting people that live full lives with rich family and social bonds, reasonably priced housing, ample winter outdoor activities (a lot of people actually want snow because it's beautiful and you can do fun things with it) and plenty of nearby nature and recreation opportunities, which I would contrast less unfavorably than the zeitgeist against the crowded, expensive vagrant culture that tends to dominate the more popular places on earth.
Wasn't it just that it wasn't yet settled, so you could settle there and claim some land? That implies that Indiana or anywhere else on the way would have been at least as desirable, but someone else got there first.