As someone who uses BSD licensed modified code at work and relies on it quite a lot, it's crucial to me choosing which projects I'm able to use in the first place.

Personally, I prefer a license that allows for commercial use in the way that companies need them to, and if my own work ever can provide a patch back upstream I'd be happy to do so, but most of what I do is just tweaking things that exist to suit my purposes which doesn't really help anyone but my business rivals which I personally am not interested in doing if I don't have to.

I prefer to have the freedom to do as I wish with the code, as compared to being bound to do as the author wishes and essentially just not using that code in the first place because I can't. I'm not in a position to change what I can and can't do because of the requirements of the business I work for, and I'm grateful to those that choose licenses that allow me to use their work.

They're creating a new browser because they want to. It started as an OS building project that the lead dev did to help stay sober.

They use discord because it's popular. Insert Ouroborus argument here, and at the end of the day it's still the most popular app.