I do understand why companies often prefer BSD and Apache products to the GPL. But what I don't understand is why companies prefer proprietary over GPL.

There are lots of evil things that proprietary software companies might do. Companies put their own profit above the rights and freedoms of their users, and to that end, much that can be done that subjugates users.

...after finding almost no information on the subject for his own purposes, Kirch decided to write a paper that compared the two systems critically. The paper covered various topics such as the costs and licensing, functionality, system reliability, management, performance and security issues, common misconceptions about both operating systems, and others.

Some critics of existing search engine products say there is a growing need for alternatives to the proprietary search companies and the big business associated with sponsored information and ad revenue from search results. A few innovators are conducting a quest for new search engines and an alternative to the influences of ranking done by proprietary search platform.

By definition, free and open source software (FOSS) is opposed to proprietary companies. But, as Jim Zemlin and Stephen J. Vaughan-Nichols have pointed out recently, the FOSS community does not regard all proprietary companies with equal disdain.

It has long been the case that proprietary software companies regularly engage in FUD (fear, uncertainty and doubt) tactics against their opponents. This particularly seems to apply to Microsoft’s statements about free software in general and GNU/Linux in particular. Recently I’ve noticed a surge in the amount of FUD going the other way—from the FOSS community towards Microsoft and other proprietary software companies. Why do we feel it is necessary to fight FUD with FUD

Tim believes that open source, at least as defined by open-source licensing, has a short shelf life that will be consumed by Web 2.0 (i.e., Web companies hijacking open-source software to deliver proprietary Web services) or by traditional proprietary software vendors.

I remain frustrated by the complete lack of marketing and business sense that many open source companies continue to display. I thought that we were past the whole foolishness of competing in the ghetto amongst ourselves vs. the big proprietary guys with lots of dough but it seems that the argument has just started taking other forms.

Open source software is successfully displacing proprietary applications in many large companies and eating into the annual revenues of proprietary software vendors by $60bn per year, according to research.