First, I think everyone should understand that some abilities are broken just because the way they work, and some are not popular just because the way they work.
And second, obviously, popularity is not necessarily the same thing as OP.
In all games, the edgy, angsty, cool looking characters get picked more. And if they have an okay, at least, ability they get picked a lot more. The counter-argument to this is why isn't Revenant more popular then, and I'd argue he's probably more popular than he would be if he looked like a big fat circus top clown. Okay, that's maybe too obvious. But another reason is Revenant started this game weak for a long time and needed a massive buff just to bring him to par. Wraith has always been strong, starting from way OP to where she is now, and she's a favorite for background story and all her aesthetic appeals.
Bloodhound, I'd argue, gets the same kind of love as Wraith aesthetically, but BH abilities are both not so obvious as to their use, and less prone to individual play. Another thing players love in a team game, especially when team members let you down...but they'd love it anyway....is when they can play a character that has nothing to do with the team. Pathfinder's design is exactly that way, all of PF's abilities useful to an individual even when running alone. Octane is weak but loved for the same reason...his abilites really aren't that great but he's picked because people like to run team games solo. Back to Bloodhound though....pretty good abilities, but definitely a character more useful on a team, so popular I'd argue but less so than Wraith.
Conversely, strong characters, or even characters who need a buff, but who shine when you play with a full team are just hammered on the list. Wattson and Crypto show that, and frankly, that's why I think Loba places low. She's new, I think people realize the bracelet isn't nearly as great as instantly traveling into another dimension like Wraith, and if you want Black Market to matter more, you need to work with your team to pick your drop points and loot to get ahead in the early and mid game. Also not such a great ability in the end game.
Wattson, Crypto and Loba can all do so much better when you play with a team. Crypto is really nothing without proper team play.
This is why you hear screaming about the nerfs, because they hurt the individual character's solo play more. Notice nobody is asking for a zip line buff, or a portal buff. They're mad that Octane has a low profile and not asking for jump pad to be more useful to the team. Everyone wants to be a rock star, the irony being that if they played characters that did well with a team they might be the rock star. But it's more like people just want to show off, and do whatever they want, and ignore playing with others which is why they get mad when the things that let them do that get nerfed.
I'll bring up my complaint again, Kings Canyon, the total Yolo map. Now, you may like it as a map, but I promise that people who love to not play with teams also love this map because it practically asks you to not play with a team. The reasons people say they hate WE and love KC are nearly perfectly in line with a playstyle that involves no team-play and communication whatsoever, because you'll do fine on KC by ignoring your team and running away from fights.
Back to the topic at hand though, because those people still play WE the same way too. I love the ideas of Wraith and Pathfinder. I happen to think the Pathfinder nerf was totally necessary. At this point, though, I don't think any more nerfs are needed to either character.
What has to happen is that other characters need to be made stronger.
TEE ELL DEE ARR; No surprises here.