There is zero reason why a salary cap should be eliminated in hockey. Without the cap, teams like Montreal, Chicago, Toronto, New York, etc would always be the top dogs. Teams like Florida, Arizona, etc would basically be facing impossible climbs of getting to the top. Top players simply bolt in free agency and form "super teams" like what's in the NBA quite often. While they may be fun to watch at times, there is no place for them.
Another horrible aspect without the salary cap is that it makes cheap owners sell for less than fair value (Miami Marlins style). The Marlins traded three top talents, including the reigning NL MVP, and got zero top 100 prospects. This is pure finances that are affecting the team in as severe a way as possible not simply baseball operations like it should be. We almost saw this anyways, with Ottawa entertaining the thought of trading Erik Karlsson along with Bobby Ryan. If there was no salary cap, it would have been extremely easy for Tampa to pull it off, and therefore forming a "super team".
It also creates more of a strategic element for all GMs up against the cap. Take my Capitals last year. They had to let quality players leave due to salary cap constraints, including trading away a top six winger in Marcus Johansson due to the salary cap. If the salary cap wasn't there, our owner certainly would have been able to pay to keep as many of these players as he wanted. It creates an unfair advantage to the wealthier teams in the league.
Taking away the salary cap is one of the worst things that could possibly happen. Even if you throw in a "luxury tax", there are owners that won't care about that. Winning is what matters most to the most competitive of owners, and they will spend whatever money is necessary. The salary cap makes everything level and gives every team a fair shot at building a champion.
@phillyjabroni can you please elaborate as to why you think having such an incredible unbalance in the league is a good idea?