I'm going to break this down because it seems like you're coming at this from a place of honest ignorance.

So build something worth visiting?

There are lots of things worth visiting that you would find if you bothered to look. For example:
The world's oldest and largest collection of military aircraft is in Dayton, Ohio
The largest cave network in the world is in Kentucky
Indigenous earthworks all throughout the Ohio and Mississippi River valleys
Plenty of small, charming, non-trumpian towns
These are just a handful of things off the top of my head in and around my home state of Ohio. It ain't Hawaii, but we do have lives. You should come and visit sometime, maybe stay for a while and help push us back toward the left. Plus, you get rust belt prices on everything ($100 for 2oz of weed in Michigan).

When your biggest draw is “the world’s largest ball of yarn”, why should people care about you? People in cities don’t ridicule you; they never even think about you. You think about them and how they live in an amazing place, constantly downplaying the benefits of living in a place that has no tourists making everything crowded and expensive.

How about starting with the fact that there are tens of millions of your fellow countrymen living here and oh, by the way, THEY GROW YOUR FOOD. If you truly believe that the only value a person or community has comes from their ability to attract tourists, then I suggest you try not eating for a week and see if that changes your mind. Believe it or not, I don't sit around all day begrudging all those awesome coastal cities out of jealousy. I don't think about you much at all to be honest. What does irk me is the fact that, when people do talk about us, it's almost always dismissive and condescending. There's east coast, west coast, the south, the southwest, and that big flat nothing in between. In shows, memes, and movies, the midwest frequently either doesn't exist, or serves as some far-off no-mans-land that the character is trying to escape. It's all tornadoes, children of the corn, and naive or racist simpletons. It doesn't have a culture, it is the absence of culture.

But who cares anyway? Ok so there's some nature and generic museums, it's nothing you couldn't find in Philly or Fresno, and the racists are still really off-putting. Why should you care? I'll tell you why; because we need your help. The midwest, and in particular the rust belt, used to be a hotbed of leftist politics. In the span of less than a century, these people have turned from ardent secular socialists to rabid christian fascists. What we're seeing now isn't just the same old assholes being assholes. Many of these people are honest-to-god fascists, and it's spreading like a plague through the center of the American continent. I'm sorry for the wall of text but this is a really personal issue for me. I've lost a lot of friends and one of the first symptoms, before the cult worship, before the authoritarianism, before the capital storming and mass violence, is "the left doesn't want me, the 'coastal elite' don't want me, the corporatist republicans won't help me, I have been politically abandoned" (obviously not literally).