Adding nonfree software to the GNU/Linux system may increase the popularity, if by popularity we mean the number of people using some of GNU/Linux in combination with nonfree software. But at the same time, it implicitly encourages the community to accept nonfree software as a good thing, and forget the goal of freedom. It is not good to drive faster if you can't stay on the road.

When the nonfree “add-on” is a library or programming tool, it can become a trap for free software developers. When they write free software that depends on the nonfree package, their software cannot be part of a completely free system. Motif and Qt trapped large amounts of free software in this way in the past, creating problems whose solutions took years. Motif remained somewhat of a problem until it became obsolete and was no longer used. Later, Sun's nonfree Java implementation had a similar effect: the Java Trap, fortunately now mostly corrected.