Kyrou has his issues no doubt, but he's also a piece of a puzzle when building a Cup team. If Tarasenko never had the Backes/Steen/Oshie line or O'Reilly/Perron line to help shelter him, Tarasenko would also be exposed in similar ways as Kyrou has. Both have moments where they look like they can have a strong defensive/2-way game, and other moments where they look useless in that aspect.
Since the coaching change, Kyrou has 14 goals and 26 points in 27 games. He's a +3 in that stretch. He's shooting 16.1% in that stretch, so it's not a wildly unsustainable rate either. A big thing for him is starting the season strong, in back to back seasons, he's struggled massively out of the game, and that can't be what happens moving forward. That's also why he gets more negative attention because people will always remember how a player starts or how a player ends, and it's very difficult to shake perceptions of a bad start, unless you go unbelievably hot.
It's somewhat similar to saying Parayko isn't a #1 dman on a Cup team, so ship him out. Obviously Parayko isn't a #1 on a Cup team, just how Kyrou isn't an all-situations winger on a Cup team, but both are at the level of playing an important role on a Cup team.