Janeway didn’t get hate as much as it was criticism of the writers for making her inconsistent. One week it was “Prime directive no matter the consequences”, the next was “Lets do whatever to make drama.”

For all of Roddenberry’s faults, his presence for the early years of TNG kept TNG consistent instead of allowing the writer of the week to change characters for their personal story. By the time he was gone, the formula was set such that writers wouldn’t mess with characters.

Voyager has no singular authority so consistency of character was rare.

Edit: Except for Ensign Kim. He was born an Ensign and died one. Nobody messed with perfection.