I'd say it's debatable. Joel might have learned to love again over the course of TLoU, but his love for her didn't lead to anything good. It just caused him to kill all the people who had the potential to end the zombie menace once and for all, meaning his love only doomed the world and brought more suffering to it. While I was always of the personal opinion that the Fireflies were a bunch of idiots who were no different from the other gangs and raiders you encountered throughout the game and their idea of a cure was just an act of desperation at best and it was never going to work, it's clear the writers had other ideas and were intending me to take everything told to me at face value. The sequel showed their true colors.