You're quite right in that corporate structures do disperse liabilities. It's there in the name - limited liability company. However there are well established standard mechanisms for balancing out that real and tangible benefit, which are taxation and regulation.
Public corporate ownership is all very well, I'm not in principle against it in certain areas. However what I suspect you are advocating is enforced public ownership, i.e. the prohibition of private companies and socialisation of the entire economy. That hits two big problems.
The first problem is purely practical really - it doesn't work. It's been tried over and over again, and is a recipe for disaster. Now I'm not saying all public companies will fail, not at all it can work fine for some activities particularly utilities and social services. I'm saying that resorting to public ownership across whole economies fails. Every time.
The second issue should really be the first in terms of priorities really. Forcing universal public ownership and prohibiting private enterprise is oppression, pure and simple. Capitalism is just the exercise of individual freedoms and rights of ownership over property and capital, and free association with others. That's it. That's all it is. You don't even really need limited liability, although I think that is a reasonable and well proven enhancement when balanced by appropriate regulation in the public interest.