But those wouldn't have been "shareable" or standard either- unless they were all shared as a group. When someone says "here are some lines from my .bash_profile"- they are not implying something by having them in bash_profile and not bashrc. No one in their right mind would think "must be something they only want to run when they log in." Instead, you take those lines and put them into your .bashrc or .profile or whatever you happen to have working well enough. Or, worse, someone says "here's my .bash_profile" and someone new to osx drops it in their home directory and all of a sudden nothing works because bash stopped looking at their .profile that already existed, while someone on linux drops it into their home directory and it looks like it's not doing anything at all.
etc. (: obviously people get it to work, and obviously "madness" was a euphemism, but I was tired of all the ambiguity.