That so many conservatives unironically identified with Homelander is proof that it absolutely needed to end this way.
Because behind all their cruelty, tough talk, and bravado; are pathetic, mewling, pieces of shit, just like Homelander. That's why they hate this ending.
The show writers turned Homelander into a Trump analogue, and this is how they choose to end The Boys.
This entire show was just a deranged sexual humiliation fantasy projected onto Trump. They can't even produce a decent superhero parody without injecting their twisted fetishes into every script.