It wasn't "up until the Rumble" and it wasn't "Bryan only". If you want to quibble with Jericho's statements at that granular a level, have at it.
Roman, Rollins, and Ambrose were massively popular in the Shield. They were massively popular when the Shield split. Big reactions.
Then The Dirtsheetz (sigh) started leaking "Reigns to win title at WM 31?" and later "Reigns v. Lesnar for title at WM31?". When that happened, it became a "guarantee" to (insert your preferred terminology for smarks) that Reigns was Wrestlemania main-event bound. That's when those who had liked Reigns turned on him: he was getting the spot that their absolute favorites (Ambrose, Bryan, Ziggler) weren't going to get. Hate was on from that moment. When the Rumble had the dirtzsheetsz rumors confirmed, the hate was solidified.
That Roman is massively popular at house shows gets dismissed here because people here don't go to house shows, consider the fans who attend to be mark ass marks, and they don't count because it's not the real crowds like on TV. Then when the crowd on TV isn't in line with what they think, it's a "bad city" or a "mark city" or some other shit. It's some sad shit.
The Kane/Show bit tossing out everyone else was actually perfect, but of course the internet hates it because they hate Kane/Show and loved who they tossed out. Kane/Show tag-teaming should be able to destroy everyone. They're giants. They should be able to ragdoll toss people out. The only way Reigns or anyone should beat them 1-on-2 is if they fight each other and lose focus.
You're supposed to hate what happened. That's the point. They were heels, bro. The problem is you move beyond hating it as a fan to "well it's objectively bad storytelling", which is false, and which is a problem with fans today I don't want to rant about again.
Truth.
They haven't helped Reigns by booking him with bad opponents, and applying the same cookie cutter formula to all of their top babyfaces (everyone has to be able to cut a 20 minute promo? WHY? I just want to watch Bryan and Reigns cut a 2-3 minute promo, and beat the hell out of people. Cena can cut 15 min promos. Great. Let him do that. Not everyone needs to be booked the same exact way.)
The new way to be heel is really to be heel on a meta level. It's kind of messed up; it's like there's a new level of kayfabe that must be held to in order to get consistent heel heat.