Because it's an idealist lie. Simple as that. They've created an idealist idea of [4 freedoms](https://www.gnu.org/philosophy/free-sw.html) and a set of licenses to enforce those 4 freedoms. While in reality, might makes right. So obviously it created tons of [GPL](https://en.wikipedia.org/wiki/GNU_General_Public_License) violations and people have been taking the code under the free software license and using it in countless closed source projects.
[GNU Project](https://en.wikipedia.org/wiki/GNU_Project) was launched it 1983, what did they achieve in a span of 41 years?
* A corrupt [Free Software Foundation](https://en.wikipedia.org/wiki/Free_Software_Foundation) which is plagued by internal drama, politics and other nonsense just like any other conventional human organization. [GnuTLS](https://en.wikipedia.org/wiki/GnuTLS) and [GNU Libreboot](https://en.wikipedia.org/wiki/Libreboot) dramas are only a tip of the iceberg.
* An authoritarian rule of [Richard Stallman](https://en.wikipedia.org/wiki/Richard_Stallman) who was pushing his delusional lie to the very end like a true cult leader.
* A [GNU/Linux](https://www.gnu.org/gnu/gnu.html) operating system which still struggles to attain 1% market share, mostly being used on servers. This fact alone shows just how extremely bad and inhuman the operating system is as it's still mostly based on the usage of terminal and all of the 1970s nonsense. I mean, it's so horrifically bad that people are still [fighting over the name of the system](https://en.wikipedia.org/wiki/GNU/Linux_naming_controversy). Of course, later Google took the same kernel and created a much better operating system - [Android](https://en.wikipedia.org/wiki/Android_(operating_system)) - which rightfully attained significant market share.
* Exceptionally bad pieces of software such as [GCC](https://en.wikipedia.org/wiki/GNU_Compiler_Collection) and [glibc](https://en.wikipedia.org/wiki/Glibc). Written in an exceptionally old-style so reading the code makes your eyes bleed, having horrible inhuman interfaces and also being profoundly bloated. People naturally got sick of it and started writing replacements. [Clang](https://en.wikipedia.org/wiki/Clang) was created as a replacement for GCC and [musl](https://en.wikipedia.org/wiki/Musl) is used as a replacement of glibc.
* A community of obedient cult followers who believe the lie and are willing to defend it on the Internet with great passion. People who have noticed all the inconsistencies - while also being inclined to mock - have labeled those followers ["freetards"](https://eldritchdata.neocities.org/GNU/REFreetardism).
Of course, wise businesspeople noticed how naive and foolish free software activists are and noticed the profit potential, so they've created the [open-source-software movement](https://en.wikipedia.org/wiki/Open-source-software_movement) led mostly by [Eric S. Raymond](https://en.wikipedia.org/wiki/Eric_S._Raymond) and [Open Source Initiative](https://en.wikipedia.org/wiki/Open_Source_Initiative). The goal was simple. To remove the rigidity of [copyleft](https://en.wikipedia.org/wiki/Copyleft) to allow the open source code to be legally used in proprietary/commercial software. So that the unpaid labor of naive people could be properly profited from. Of course, as much more tolerant and "user-friendly", open source movement by far have surpassed the rigid cult of free software, proving once again that Richard Stallman's vision have always been a lie.
So. Unlike free software movement (or even open-source-software movement), this movement is utilitarian. It recognizes that everything is a tool. So use whatever software you're comfortable with. The license doesn't matter much. However, it also recognizes that forms of "intellectual property" such as copyright, patents and trademarks are forms of greed and the more people are enlightened, the less greedy they are so all the time and effort spent on copyright, licenses and enforcing them is wasted because of the human greed and the old system that fosters it. So it seeks to abolish the greed - the root cause of the problem.
People are exactly as they are. You either write a software for people and people will use it, giving you loyalty, money and market share, or you write a software to pander to your own delusions and will either stay alone, be known as another cult leader or [Terry A. Davis](https://en.wikipedia.org/wiki/Terry_A._Davis).
*"If you build it, they will come." - [Mandela effect'd](https://en.wikipedia.org/wiki/False_memory#Mandela_effect) from [Field of Dreams](https://en.wikipedia.org/wiki/Field_of_Dreams)*
