I liked this film and I'm sorry I waited so long to see it.
Like The Landlord (1970), this film deals with everything in the world. Four Friends, in particular, deals with everything bad in the world, like social class, racism, war, bad parental relations, physical disabilities, exploitation of immigrant labor, violence, etc..
If you are looking for some reason that this movie didn't take off or thrill audiences, I can give you about six reasons:
This movie essentially has six starring roles in it. None of those people were even remotely famous, and none of them has gone on to amount to any kind of a big movie star. I think the acting was great and everyone did their role well, but casting is casting, and it looks as if they said, "okay, pick us out six actors that no one knows, no one likes, and no one will ever like" and put them into the film.
You said that this movie "Doesn't Click with Audiences, Somehow", but not a single person in this film has every clicked with anyone.
I'll show the flip side of this, from lousy casting to brilliant casting:
Less than one year after Four Friends came out, another movie came out. No one in it was even remotely famous, and nobody got paid any real money to be in it. The totally unknown people in that film were Forest Whitaker, Nicolas Cage, Sean Penn, Jennifer Jason Leigh, Judge Reinhold, Phoebe Cates, and Lana Clarkson. Phoebe Cates isn't even any kind of actress and hasn't really done movies in 15+ years, but she is more famous than everyone in Four Friends combined, including the director and writer.
That is called massive star power and that is what casting people know how to sniff out. That is what brilliant casting is. What was done on Four Friends was, well, what's the opposite of brilliant casting?