I have the chrome extension that others have mentioned already installed but I'd still like to see this as a default on the site rather than something only a fe

I have the chrome extension that others have mentioned already installed but I'd still like to see this as a default on the site rather than something only a few have. For one thing I imagine it would spread out the conversations in threads better. Currently most threads have one comment with a lot of replies at the top and not much going on below it. Is there some stated reason why there aren't currently collapsible comments?