He's ruined the Senators. They had a great run at drafting and developing players and trading those that didn't fit for as good if not better talent. That ended when he took over.
He completely botched not only the Heatley deal, but again with how Alfie was handled , acquiring Ryan for a slew of picks and prospects (he got fleeced) and now for not moving Spezza for immediate picks that would obtain him valuable young players thinking that Spezza and his soon to be expiring contract next summer is going to return him the same.
Even then, his 2 good drafts, a lot of which could be credited to his nephew (Who frankly I'm not totally sold on) have really only produced Karlsson, who is an enigma and plays more of a rover role, not a defensive one. He should trade him while the value is high.
Melnyk's gonna need to dump his staff and start over soon. They won't contend with that idiot running the show.