This is kinda of an idea for Fallout 4, but also a question as to why is hasn't been included in previous games.
I know about the Fallout 4 Ideas and Speculation thread, but I feel this deserves a thread of it's own.
If a mod disagrees, no hard feelings in closing the thread

Now, back on topic, why hasn't there ever been something like an open pool for followers (companions) in Fallout? What I mean is where you can recruit *almost* anyone in the game as a follower, excluding important main quest characters for obvious reasons. Now, obviously these characters wouldn't ALL have their own story, and we would still have our usual main companions and all their background stories, but I feel this would open the game much more to be able to have almost anyone help you on your way.

Just a thought I had while doing Arcade Gannon's quest in F: NV.

I don't know how that would work. Would you just go up to a random NPC like Sunny Smiles and ask her if she would like to go explore the wastes with you or.... what. Because from a story standpoint just asking people wheather or not they wuold like to go with you doesen't make much sense.