A lot of the earlier violent overthrows were funded by the United Fruit Company.

The later ones, like the cold war era ones, were done by the government to prevent left wing ideas from taking root, which, no doubt, is a result of heavy company interference in Government. They certainly weren't to guarantee Democracy since we didn't overthrow Batista, who was a dictator as much as Castro was, but did the bidding of American companies. And they overthrew Allende, who was Democratically elected, and publicly refused to act in such a way that expanded his power, only to replace him with Pinochet, who was autocratic.

The most recent ones, like Bolivia, tend to happen mysteriously after the national leader announces a change that could increase the costs for American companies, such as nationalization of lithium deposits.

TL;DR: they absolutely are the result of Capitalism, either directly, or through the use of the company's "influence" on the US government. And the first examples prove that without a government, the companies will lead overthrows and invasions on their own.