First of all, the idea that there exists such thing as a "real fan" and a "fake fan" is bullshit, even if someone only enjoyed Fallout: Brotherhood of Steel for the original Xbox, they are a real Fallout fan, same for people who only enjoy Fallout 4 and 76, same for people that only enjoy 1, 2, and Tactics, and so forth. Fans are fans.

Am I pleasable? Absolutely. Bethesda largely just needs to drop the "eternal apocalypse" bit and always having to come up for new excuses for why the world hasn't rebuilt significantly and either rebuild or set their games earlier.

Another good thing would be to stop recycling factions that logically shouldn't be recycled so much, like Super Mutants and the Brotherhood. They haven't done the Enclave to death quite yet, but that's still something that should have largely been wiped out in 2, not come back even harder in 3.

Another good one is overall tone: Fallout works best as a black comedy, where overall it's serious, but sometimes the situation itself can be wackier, not a non-stop barrage of jokes and an overall lighter tone. 1 and New Vegas nailed it, 2 and 3/4 didn't IMO.

Is it not valid to have those opinions? Bethesda treats Fallout like an Elder Scrolls series more than a Fallout series, they focus on exploration over roleplaying and good quest design.