That's a gross generalization. Pretty much every legal business is some type of corporation. Is your local bakery "systematically ruining our country?". Is a farmer growing strawberries ruining our country? Corporation just means legal business. These businesses provide jobs to the majority of Americans and services to the community. Without corporations, the whole country would fall apart.
Are there bad corporations? Sure. But that doesn't mean every corporation is bad. The overwhelming majority of corporations are small businesses. Small business owners aren't bad people in general.
Me opening a legal corporation to grow/dispense cannabis doesn't make me a bad person or mean I'm doing anything to ruin the country.
Now if you want to say the concept of publicly traded corporations are evil, I could see where you are coming from. But to say all corporations in general are evil is just ignorant. A corporation is a thing. It's a business tool. That's it. It's incapable of evil. That's like saying forks are evil because you can stab someone with one.
It's people that are capable of ruining the country. Those same people are capable of doing the same bad things if prohibition is around or not, so prohibition might as well not be around.