> I've seen few times that people abuse npm to do install of software that is not js, but why force me to install npm?

The "npm distribution method" is for people who already have npm installed, just like apt-get instructions are for people on Debian/Ubuntu, you're not meant to install apt if you happen to be on CentOS, just like you're not supposed to install npm if there is a better installation method for you. Sucks when it's the only installation method, same with curl|bash, I tend to just close the page when that's apparent, haven't missed anything so far.