It goes back a long ways and it stems from very minimalist only free software linux communities. Many of these communities I've been privy to for 15+ years take pride in running in the smallest memory footprint, are anti-Java, anti-javascript, anti-Poettering (systemd as a backdoor), etc. and this is the premise of it. This community will get very mad at you for suggesting to add in those things that they deeply hate, i.e., javascript or non-free software blobs.