Their backgrounds are also very similar; they are all young and from small, isolated communities with little knowledge of the world outside their small worlds, but with the potential for greatness. The Vault Dweller and the Chosen One also have a very believable motivation: saving their communities. This in turn transitions believably into a larger and even more heroic motivation of saving whole regions. The Lone Wanderer is driven by his motivation to find his father and after his father's death to fulfill his dream and ideals.
Once the Courier has found who shot him and what he was shot for, why does he continue to help any of the main factions? What does he accomplish or gain by choosing a side in a conflict that could cost him his life?
Spoiler
He can talk to Caesar and hear his take. He seems sincere in his beliefs and his desire to move society forward, but these are Caesar's motivations, not the Courier's. Is the implication that the Courier was persuaded to risk life and limb for Caesar's cause after meeting him once? Where's the urgency? Where's the incentive? What's the payoff? A gold coin?
The Courier can talk to House. He also seems sincere in his beliefs and his desire to advance the human race, but he at least explicitly says you will be rewarded with more than enough riches. That could be enough motivation for some, but beyond that, as with Caesar, you have to believe and buy into his view and goals. He was already a little crazy before the war, but he was also very right in his predictions. It's a gamble.
The Courier can choose to keep helping the NCR. The problem here is there's no reason to fight someone else's fight. It's not his country. He's not promised wealth or power (not even a military commission). He's not given any indication that the problems voiced about the NCR, including by its own citizens, are untrue. Is it all really worth a merit badge?
The Courier can also talk to Yes Man and hear all about Benny's plans. This is the most unclear of the unclear paths it seems. Are you taking control of the securitron army for yourself as Benny planned for himself? That's pretty good. You rule Vegas right? Well, no, apparently this path means you're freeing New Vegas and making it "independent", but you don't know that till the end and even then Yes Man's dialogue hints that he may become a problem, and it's never explained how this independence will function. Are you in control after all? Is Yes Man?! And you are just a person people talk about.
The Courier can talk to House. He also seems sincere in his beliefs and his desire to advance the human race, but he at least explicitly says you will be rewarded with more than enough riches. That could be enough motivation for some, but beyond that, as with Caesar, you have to believe and buy into his view and goals. He was already a little crazy before the war, but he was also very right in his predictions. It's a gamble.
The Courier can choose to keep helping the NCR. The problem here is there's no reason to fight someone else's fight. It's not his country. He's not promised wealth or power (not even a military commission). He's not given any indication that the problems voiced about the NCR, including by its own citizens, are untrue. Is it all really worth a merit badge?
The Courier can also talk to Yes Man and hear all about Benny's plans. This is the most unclear of the unclear paths it seems. Are you taking control of the securitron army for yourself as Benny planned for himself? That's pretty good. You rule Vegas right? Well, no, apparently this path means you're freeing New Vegas and making it "independent", but you don't know that till the end and even then Yes Man's dialogue hints that he may become a problem, and it's never explained how this independence will function. Are you in control after all? Is Yes Man?! And you are just a person people talk about.
Something else that seems to have been completely sidestepped is why the Courier is not trying to find out who he is. It seems like that would be a pretty powerful urge for most people, and it seems pretty easy to resolve given his connection with the Mojave Express and the area. He was hired to deliver the chip from Primm to the Strip. The odds of him being a local are pretty high.
The premise of the Courier seems especially weak compared with all 3 previous Fallout game protagonists.