[joshAg]

> Why are acquisitions legal?

It'd take at least semester of public policy, a semester of economics, a semester of history, and a semester of legal studies to adequately answer that.

The shorter answer is that nonnatutal persons and natural persons have the same rights to do what they want with their property, barring very specific exemptions. One of those exemptions is monopolies, but (and add this to the list of shit Ronald fucking Reagan and the university of chicago screwed up, too) in the 1980s US anti-monopoly enforcement switched from focusing on ensuring a competitive marketplace to focusing on ensuring economic efficiency and consumer welfare, so it became much much much easier to merge and acquire competitors.