Except we are not getting a Kotkaniemi type prospect in a Patch trade. We are after draft picks. We would be extremely lucky to draft a grade A prospect. The question and answer is different based on what team you ask. Some teams need a Kotkaniemi type prospect more than Patch cause they are rebuilding and some teams need Patch more cause they have few holes in their roster and they want to compete for a cup.
All you are doing is proving my point.
Ottawa was expecting to compete this year, and now they're staring down the barrel of a Top 5 pick being forfeited for 2 years of Duchene. The risk of having that happen to someone who isnt a true contender is likely to scare most of them off from making that trade until at least the deadline.
Conversely, while a contender may be looking to add a productive player, more and more we are seeing that teams are defaulting to keeping a productive ELC and extending the window.
All this is beside the original point of mine that context is extremely important when it comes to asking why "a proven 30 goal NHL player isn't worth a first round pick".