Yes. There are several sections on gnu.org that talk about this, these are the ones I was able to quickly find.

https://www.gnu.org/philosophy/free-sw.html

You should also have the freedom to make modifications and use them privately in your own work or play, without even mentioning that they exist. If you do publish your changes, you should not be required to notify anyone in particular, or in any particular way.

https://www.gnu.org/philosophy/free-software-even-more-important.html

The freedom to make and distribute exact copies when you wish. (It is not an obligation; doing this is your choice. If the program is free, that doesn't mean someone has an obligation to offer you a copy, or that you have an obligation to offer him a copy. Distributing a program to users without freedom mistreats them; however, choosing not to distribute the program—using it privately—does not mistreat anyone.)

https://www.gnu.org/philosophy/categories.en.html

Free software is a matter of freedom, not access. In general we do not believe it is wrong to develop a program and not release it. There are occasions when a program is so important that one might argue that withholding it from the public is doing wrong to humanity. However, such cases are rare. Most programs are not that important, and declining to release them is not particularly wrong. Thus, there is no conflict between the development of private or custom software and the principles of the free software movement.

Nearly all employment for programmers is in development of custom software; therefore most programming jobs are, or could be, done in a way compatible with the free software movement.