I don't think Shero has done a bad job in NJ, he did amazing to build a team offense. But look what he didn't do, he didn't do anything to hire a guy that can coach defensive structures or really upgrade a core majority of his defense. Now the team looks worse this year with their best offense in years.
That is why the Devils shouldn't have gotten rid of Lou. It was so foolish. The team literally lost their 2 top players in consecutive years and their core aged. It was time for a rebuild, and the owners just handed the reigns over because "he's old!".
Look what Lou did in Toronto, he turned the franchise around. Then he left and the new overrated GM there made the team regress and has given some horrible contracts. Lou then goes to the Islanders, turns the franchise over there immediately. He is the best GM ever, nobody has done what he has done on new teams. Also, him winning 3 cups with NJ who barely spent any money in a non salary cap era demonstrates his greatness.