Simple to write yes, but also very juvenile. "Humans are the bestest of the best! Everyone wants to be like us!" It was very disheartening to see the Geth treated like this in ME 3, so much so that I have come to using the term: "Pulling a Geth" when something similar happens in other sci-fi settings.
Yeah, it's a shame that they were treated like this.
I mean, the Pinocchio treatement for EDI worked because she was a human-built AI that was designed to work as part of a human crew, so I could buy her wanting to learn more about humanity, as it would allow her to better interact with and function alongside her crew?
But the Geth are completely alien, even more so than most of the aliens in the setting. Their origins are also not the same, while EDI was designed to be an AI, the Geth were never meant to be self-aware. EDI has spent most of her time in constant contact with humans, whereas the Geth have been apart from their Creators and most organics for centuries. If the Geth were meant to "evolve" towards a sense of "humanity", it should have happened long before now, showing that this is simply not the direction that they are heading towards as a "species".
Rather than the Reapers or Geth developing true individuality, I suspect that they are more naturally predisposed towards developing personality quirks if they are active for long enough, or seperated from their compatriots elsewhere? Harbinger, as the first and oldest Reaper, shows signs of a very distinct personality, as does Sovereign, the lone vanguard left behind in the Milky Way. Likewise for the Geth, Legion develops a few character tics after his time amongst organics in ME2, which aren't present in his backup copy in ME3 from before he left the Perseus Veil.