Because he's the last thing we need to win a cup.
If we have another pick at 15 and he's still there, sure. I like him quite a bit, but not for the Habs. You can't have Caufield AND Catton. It's one or the other. Plus, we have Newhook, which is in the same format as well. Suzuki isn't giant either; we have to take that into account. If Suzuki was as big as Barkov/Drai, it would be a different story.
Look at the top 8 teams in the NHL, they don't have a collection of these players.
No more than 1 undersized, with no physical dimension, and "not fast" player in the top 6 or bust.
Obviously, Demidov is the target here:
Necas(or another trade) - Suzuki - Slafkovski
Caufield - Dach - Demidov/Lindstrom/Iginla/Sennecke.
Roy - Newhook - Mesar
Evans- Beck -Gallagher