>>712493357Prioritizing Sakura is a compromise. Shirou will always having a lingering void in his heart that compels him to go out and save people. It's a compulsion that will never truly go away. But he's unwilling to sacrifice Sakura in the pursuit of that goal, so he settles for being her hero instead. Whenever he sees people suffering on the news, he'll feel that pain, that compulsion to go out and do something. But he'll ignore it and force it down for the rest of his life. In a sense, it's a denial of his own identity, but he deems saving Sakura to be more important.
In UBW, the main reason Archer was so angry was because he sold his soul to become a Counter Guardian. So long as Shirou avoids becoming a Guardian, he'll avoid Archer's fate.
Ultimately, the reason you prefer HF's ending is because YOU personally find that ending to be better. You want Shirou to adhere to YOUR principles because you believe your own principles to be superior than Shirou's. You feel disgust when Shirou becomes a hero because you disagree with it, because you believe Shirou should think like you rather than form his own conclusions. This is the crux of everyone's problems with UBW.
>"I don't like this, so Shirou shouldn't like it either."