'Make -j 10' is "ugly"

[Chocanto]

In the readme at the section Linux (https://github.com/ValveSoftware/vogl#linux) you can see in the list of command this one :

make -j 10

But the make manual, about -j, tell (https://www.gnu.org/software/make/manual/html_node/Parallel.html) :

If there is nothing looking like an integer after the ‘-j’ option, there is no limit on the number of job slots.

So why not just execute make -j ?

[Plagman]

Because that will most likely cause your machine to swap unlike -j10, depending on the size of the project.