He is. I never understood why people use that argument. A non-productive NHL forward would not get the time of day on those lines. Apart, he's still a bottom six caliber forward and was willing to add a physical edge prior to the trade last season.
He's a fast, physically imposing forward that wins puck battles. There's room for a guy like that on teams if he's committed to improving. There are a lot of weaker players out there who have roles.
When that player is a former Top-5 pick, they absolutely get the time of day to try to salvage something out of them. Heck, even Jake Virtanen got a run as a Top-6 Forward even though he had a lot of the same problems as Puljujarvi.
Sure, he's big and can be a physical presence, but he lacks the hockey sense to apply those tools effectively. He has also always lacked the agility and effective stick to be useful in that sort of role.
Just being big size and a former high pick will get a guy a ton of extra opportunities, but it still has a shelf life. At the end of the day, if he's missing the critical tools to apply the tools he
does have effectively, he's just not a useful NHLer.
He's never been physically imposing as an NHLer because it's just far too easy to spin out of his path and he can't adjust. The hits he did make when he was "healthy" were often completely out of the way of where he really ought to be. He was also below average in "puck battles" because his actual handling of the puck even if he won it, was poor. He's not a good passer, and moreover, he really never demonstrated any awareness of how to use his stick effectively to control lanes and dictate play defensively and on the forecheck. He just sort of barged in out of control and sometimes made contact with someone.
A lot of smaller, physically weaker players are massively more effective on the forecheck because they understand how to apply pressure intelligently.