Why would you have somebody make an emotional sacrifice if you know ahead of time that you're going to bring them? Sure, it makes sense in universe, but you can't just take a common trope and see how it would play out realistically.
To me it gives a paradoxical end for impact. Like picture if homu really just went to heaven with madoka, then what? But with this ending, holy shit does /a/ not shut up about it. That's my take on it.
It was only emotionally paradoxical. It made perfect logical sense.
Homu was given power over time so that she could execute her wish. When that was no longer effective, she was given power over much more.
I don't think we're gonna get along very well.