The only reason I would see is for those building SFML on Linux and never done it. I would expect somebody that does so knows how Linux works in general so it wouldn't be a problem, but some don't. And googling the exact name of the dependencies takes 5 minutes top. I've just done it myself, never had done it before. Wasn't hard to find the name of the lib I needed. Within 5 minutes, SFML was installed and I made my things work.
All I see from such a subforum is people not wanting to search and understand. If they never learn how their toolchain and environment works, they'll never get better(not true, but you get the point). I'm with Jesper Juhl on this.