It isn't a no risk move. There is a large opportunity cost attached to taking on that contract. 17.4M in cap over 2 years is a massive asset to give up. The Penguins just got a 3rd+5th for 2.5M in cap to take Joseph, San Jose got a 3rd to take 3.25M in Ceci, St.Louis got a 3rd to take about 6M in Joseph. That isn't to say those players are all exactly equal.
The risk is that if Laine doesn't bounce back, and slogs through the rest of the contract, the Canadiens are losing out on major assets that they could have acquired with that 17.4M in space.
The reward is that if Laine bounces back and is a big body 30-40 goal scorer, they will either get a big return for him in a trade, or extend him as a member of their core.
I do not like Canadiens fans because they are the worst, which is a valid reason to dislike them, but I'm not going to be surprised that a fan base in a rebuild is excited about the idea of acquiring a massive former superstar who is only 26, and is a year removed from point-per-game status.
I am unsure what his personal/health issues were or if it has come out, but I would guess it played a factor, combined with his poor commitment to his overall game. This isn't his first "change of scenery", but I get Canadiens fans just enjoying the acquisition.
People here are just salty because all these moves remind us of how badly the asset acquisition portion of our rebuild went due to our inability to weaponize our cap space under Melnyk, and the directive for Pierre Dorion to "win now" by giving up a 2nd for Derick Stepan because is signing bonus was already paid.