There is a very nice quote by Alberto Vázquez-Figueroa (Spanish writer and inventor) which reads:
"El éxito o el fracaso de un invento no depende de a quien beneficia, sino de a quien perjudica."
Which translated into English means:
"The success or failure of an invention does not depend on who benefits, but on whom it harms."
I strongly agree with it.
Suppose that somewhere in the world there is a company called Acme. This company invests resources to develop and maintain a tool A that offers a certain functionality X. This tool is proprietary, and brings revenue to the company.
Imagine that a developer or a group of developers decide to build a tool B that offers the same functionality X. They decide to release this tool as open source or free software, so that everybody could benefit from it and be more productive.
(Please don't misunderstand me. I'm not talking about stealing intellectual property or anything illegal/malicious, but the total opposite.)
In this new scenario, any individual would be able to use tool B for free instead of paying for tool A. Even worse, other companies that are in direct competition with Acme could use tool B in their workflow at zero cost, and even modify the source code to include new functionality and resell it as their own product.
What would be the outcome for Acme? Would building an open source alternative like tool B put Acme at risk?
Has this ever happened in the real world?