Some criticize the era as having a playoff system which was too easy (only two teams were eliminated after the regular season) and featuring too many dominant teams (Montreal never missed the playoffs between 1949 and 1967 and Detroit and Toronto only missed three times each, leaving the other three teams to compete for the one remaining berth).
Beyond that, rosters were very static—until the burgeoning of career lengths in the 1980s, only one twenty-year player in NHL history, Larry Robinson, started his career after 1964, and it is generally accepted that the weakest Calder Trophy winners of all time were selected in the 1950s and 1960s. In partial consequence, the league was almost entirely composed of Canadians who had come up through the junior and minor pro leagues. American, European, and college players were all but unknown.
After World War II, all six NHL owners consistently rejected any bids for expansion, and in the eyes of many observers changed the criteria for entry every time with a bent to defeating any such bid. They also reneged on promises to allow the still-extant Maroons and Americans to rejoin the league.
While many books on the period focus on the high level of play, giving it glowing terms such as 'golden era', it was also a period of corruption, where teams were found to be 'scalping' their own tickets and hiding ticket sales for the purposes of avoiding taxes on the proceeds.
The league tolerated monopolistic practices by the owners. At one point, for instance, Red Wings owner James E. Norris effectively owned the Black Hawks as well, and was also the largest stockholder in the Rangers. He also had significant influence over the Bruins by way of mortgages extended to the team to help keep it afloat during the Depression. Players who got on the wrong side of their team owner were often harshly punished for their actions. A chief example of this can be seen in the case of bruising Red Wings forward Ted Lindsay who, after agitating for a players' union, was sent to the last-place Black Hawks. Mr. Norris' conglomerate did not invest in Boston, Chicago and New York; these teams mostly just filled dates for the Norris arenas. A measure of the dominance of Detroit, Montreal and Toronto in the era can be seen in that between the Bruins' Stanley Cup wins in 1941 and 1970, every single Cup (save for Chicago in 1961) was won by the Red Wings, the Canadiens or the Maple Leafs, and those three teams failed to make the playoffs only eight times combined in the era.
Labour conditions for the players were also poor. Players' medical bills were paid only until two months after an injury. Players were routinely demoted to the minor leagues as a form of punishment. This hurt the players by reducing their salaries, and players' relocation costs were not covered. The players were not paid for off-season promotions, or shared in the funds of promotions such as trading cards, such as was done in baseball. In the earlier era, players were allowed to play other sports, such as lacrosse, for money in the off-season. This was disallowed in the standard contract.
The pension plan, formed in 1946, while ostensibly for the players' benefit, was kept secret, hiding large amounts of money under the control of the owners. The pension plan was only exposed in 1989 where it was found that a $25 million dollar surplus existed. The labour conditions lead to several players' disputes including a 1957 anti-trust action and attempted union formation, and subsequent actions in the early 1960s by Bob Baun and Carl Brewer, leading to the 1967 formation of the NHL Players Association.
By the 1960s it was becoming increasingly obvious that if the NHL did not expand, a rival league would fill the void. The American Football League was proving to be highly successful at this time, convincing many people that a rival hockey league would also succeed. In particular, the Western Hockey League had moved into a number of major Pacific Coast markets, and had accumulated strong rosters with talent barred from the static rosters of the NHL. This, plus the prospect of more lucrative U.S. television contracts finally convinced the six owners to go ahead with expansion.
All six of the Original Six franchises are still in existence, with no major identity changes (though the Black Hawks resumed their original name "Blackhawks" in 1986), and no relocations to other cities.
Though 1942 is the widely accepted year for the beginning of the Original Six era, it was not until the 1959-60 NHL season that every active player had played for Original Six teams only. The last player who did not fall into this category, former Brooklyn Americans player Ken Mosdell, retired after the 1959 Stanley Cup Playoffs.
The last active player from the Original Six era was Boston Bruin Wayne Cashman, who last played during the 1983 Stanley Cup Playoffs. The last active goalie from the Original Six era was Rogatien Vachon, who retired in 1982 with Boston.