He was relied on heavily last year by Hunter and Co. to solidify the defense. Once they moved away from giving heavy minutes early to Bahl, McIsaac, and Smith, Canada's defense improved tremendously. His TOI increased steadily over the tournament to the point that he routinely logging over 20 minutes plus per game and repeatedly led a Gold medal winning Canadian squad in per game TOI on defense. Byram was also on the ice for only one 5v5 goal in the tournament last year. Bahl, McIsaac, Smith, & JBD were all on the ice for five plus goals each last year.
Byram was again logging heavy TOI in the prelim game this week that resulted in a shut out. He was third on the team in zone exits (behind Harley and Dach) and second in zone entries (behind Dach). He assisted on Canada's only goal when he astutely recognized that Russia was in a line change and pushed the play. He almost assisted on another goal when Askarov made perhaps his best save of the game on Krebs.
The criticism does seem odd under the circumstances. I will say that more than a couple of the most critical posters are the same ones from last year, which appear to be a mix of disgruntled Devils fans (due to back and forth bickering over the possible Hall trade), Ottawa fans (for obvious reasons), and Anaheim fans that are upset that he is stealing the limelight from their prospect (Drysdale). Drysdale happened to have a bad defensive zone turnover in the third period of the prelim game, yet no one seemed to notice, which was strange under the circumstances.
It is the same thing every year. I recall some bashing of Makar, much of which seemed to come from Vancouver fans that for some reason felt threatened in relation to their prospect Hughes.
It is hard to take anything said with anything more than a grain of salt, because virtually all of it on these WJC threads seems to come with an agenda.