Why don't we just ban the buying, selling, and merging of companies?

With the ever-growing stream of acquisitions and mergers, it got me thinking: Why do we permit companies to do this?

What would the harm be in banning this practice? If a company is becomes insolvent, release all of it's IP to the public domain, dissolve all patents/trademarks, and sell off physical assets to pay debtors (first of which should be former employees IMO, but that's a separate discussion).

Edit: I think my original intention of the post to kick off some interesting discussion has worked. Thank you to all current and future posters!