Corporations or any other business exist solely on one purpose: to make profit. If you're not making any profit you're not doing business, you're running a charity.
That's why you can't trust corporations when it comes to anything "open" and "free".
There is some nuance required here, since ‘corporation’ is such a vague term. Even Mozilla Corporation, which is wholly owned by the not-for-profit Mozilla Foundation, is a for-profit organisation (i.e. it aims to turn a profit and is taxed) which which reinvests its profit back into Mozilla’s projects and and other work which Mozilla considers to be in the public interest for a free and open Internet.
Everyone has to question the stated goals and desires of corporations, and ask things like e.g who is the corporation accountable to (shareholders? themselves?) and how open is the corporation about how it invests its profit. Attempting to turn a profit is in itself not necessarily an indication that everything they do is in the sole pursuit of profit for itself.
Mozilla plows all of the money it generates back into the products and services it develops. The goal is sustaining the Mozilla project and its work, not making/taking a profit.
This is too reductive a view: companies need to be financially viable to survive long-term but people absolutely found businesses with goals in addition to paying their bills and there's a spectrum of how profitable they need to be — Ubuntu, Red Hat, and Oracle are all Linux vendors but their approaches and degrees of aggressiveness about pursuing revenue vary considerably due to differences in corporate culture.
