The GPL radically changed the IT landscape in the last decade. Whether or not it achieved all of its initial goals (as interpreted by the author of this post) doesn't mean that it hasn't been a massive, disruptive force in the IT world.
I honestly don't mean to troll, but Apple, for example, has built an entire business on open source (but primarily not GPL) software components. They used GCC insofar as it met their needs, and then switched to something else when the GPL became an obstacle. Likewise, most companies use Linux because it's a pragmatic choice, not because of the license.
I think it's overreaching to claim that the GPL has changed the landscape. Liberal open source existed before the GPL, and will continue to exist if the GPL where to somehow disappear.
* BSD-derivative Operating Systems (code available with first releases since in 1977)
* Sendmail (1983)
* Apache HTTPD (1995)
* Qmail (1997)
* MIT Kerberos (late 1980s)
* UMich LDAP (now OpenLDAP) (1995)
Modern examples are considerably more numerous, ranging from Apache Project's Java projects, to LLVM.
The places where the FSF and GPL have really succeeded are where there was usually a strong network effect (compilers and operating systems are large individual undertakings, for instance) and limited downside to the use of the GPL.
[Edit] I realize that some fringe downvoting GPL proponents take offense at the idea that the GPL isn't single-handedly responsible for mass adoption of open source, but come on guys, there's a long and rich history of commercial open source adoption outside of the GPL.
Whether by dogma or community forces, something about the FSF and the GPL transformed open source from a licensing scheme to a movement that produced the mass of software that we have today. Whether or not the BSDs could have done that is a separate question -- they in fact did not, and the massive disruption that we've seen has been an outgrowth of GPLed projects.
Speaking only in terms of operating systems, the AT&T lawsuit caused the BSD derivatives to stumble just as they started, and at the same time Linux was beginning to enter its stride. The GPL/FSF didn't (through dogma or community forces) drive this, but rather, circumstances and a general hobbiest interest in open source operating system development.
Whether by dogma or community forces, something about the FSF and the GPL transformed open source from a licensing scheme to a movement that produced the mass of software that we have today. Whether or not the BSDs could have done that is a separate question -- they in fact did not, and the massive disruption that we've seen has been an outgrowth of GPLed projects.
That's vastly overstating the reach of the GPL projects. Everything from Apache HTTPD to PHP to Perl was (and is) liberally licensed.