You clearly did not play the Replicated Man quest.
I handled it the "good" way the first time and thought it an utter letdown. I'm in the middle of doing it "evil" right now and you're right...this does seem a great addition to the series. Unfortunately it is just a mini-story with no real lasting effect or consequence. It's really no better than any mini-quest from Fallout 2...even the Smiley the Trapper quest for instance, is about as consequential and Fallout 2 is made up entirely of these sorts of moments. FO3's best moments seem to be as good as FO1&2's most pedestrian.
I see Fallout 3 as a bridging game - and beacuse of that harold needed, yes, needed to be there, as did the BOS, and the Enclave. I see both Harold and the BOS as the "Alternate" players in the world - Like it or not, when something big happens, they're there, doing what they think is the right thing to save the world from itself (The Classical BOS in saving knowledge/tech - and lets not forget they were planning to deal with the mutant threat on the west coast (once they could verify the thread), and trying to find a way to solve the enclave problem).
I hear you knocking but you can't come in. No seriously, nobody
had to be there. Like I said, unlike many old Fallout fans who were up in arms about Harold, I actually liked that whole part...but for the sake of argument no. No he was not needed. Fallout is Fallout and nothing in Fallout 1 was necessary in Fallout 2 to let you know it was a Fallout game. A few references or appearances (maybe a lone wandering random encounter with an Enclave deserter, for example) would have sufficed. Some of these things make sense on a topical level as to why Bethesda put them there, some don't and some I'm quite ok with...especially the creatures.
But there are plenty of openings in fallout 3 for fallout 4 to be the proper Beth Fallout. The Insitute and the Commonwealth are shaping up to be very powerful mysterious forces, Rivet City is looking to be a good "new" NCR style force, Talon Company isnt going to disipear, and the Regulators can be built and extended upon too. Some elements needed to appear in three, so they could be completely gone and "dealt with" by 4 - The Enclave, and to a lesser extent, Harold.
Talon was a good start...but how dynamic or memorable is a faction you can't even interact with? Rivet City? The whole 12 people that live in this supposedly ginormous city? *shakes head sadly* I just don't buy it. The Regulators were from FO1. I'll give you the Institute and Commonwealth...IF they decide to flesh it out and deepen it contextually. Anyway, I hear what you are saying...and I'm not THAT upset about it all...but it is this kind of "lack" which is preventing me from seeing this as a great game. Instead I see it as an entertaining time-ditch.
I feel confident in saying that had they not included any of the older factions people would have complained as well (probably even more).
Oh for the love of...
You know, I almost made a disclaimer so that we could avoid this very comment you just made. I
so knew it was coming...and yet it is unfortunate because you obviously merely took what you wanted to take from my post and missed the point. I'm not talking "any" and...*clenches fist, releases, shakes head* you know what? If you can't go back and understand the real point I was making then just forget it. Not worth my time.