The unspoken assumption behind your comment (and much else on the page) is that it's important for 'open source' to be accepted by big business.
Because some things (for this thesis let's say it's a crypto algorithm) work much better when they are visible to all parties, and those with a vested interest commit themselves via development time instead of cash. If you need a good crypto algorithm and you pay a closed source company for it, either you or the company you paid had better employ an army of mathematicians in order to validate that the process is secure, otherwise it could have (probably does have) a flaw just waiting to be exploited. Your investment, as a business, can only go so far. With an open source solution, everyone can see the algorithm and offer their input on its efficacy.
Open Source is the ultimate economy of scale in the information business (driving cost per unit down while selling/utilizing more) so every business with even a modest investment in software should care. There are plenty of ways to innovate in closed ways (at least, ways proprietary to your company) while taking advantage of open source technologies. The problem (to expand on the original summary) is that most uninformed decision makers jump to the conclusion that if the software was developed for nothing, it's worth nothing and furthermore that anything they do with it will be worth nothing because their innovations will somehow get gobbled up by the open source monster, too. For someone who doesn't really add anything (companies trying to get by in niches, strongarming markets, exploiting cronyism, etc) there is plenty to fear. Meanwhile Google, Apple, Facebook, IBM, Cisco, etc would casually disagree (and gladly sell you some open source software).