I'm a huge fan of Lemieux.
No - it doesn't make him less of a talent. In terms of legacy? It would have been a HUGE hit on his career without the playoff success he eventually achieved. Lemieux is part of the 'big 4' today, and many argue him as the most talented/skilled of all time. Many say he could have made a run for #1 with good health. I think all of those compliments towards Lemieux don't even register if he didn't prove it he could also do it in the playoffs. It's not just the cup wins - it's the smythes, and some of the most dominating smythe wins of all-time.
If McDavid hopes to one day reach an all-time great status, worthy of being looked at as a top 10 player ever, and maybe in contention for #5 (as Crosby is) - he'll have to have a playoff legacy worthy of it.
I do agree with you that if Lemieux built his playoff legacy after age 24, so can McDavid. It's still early. But - he'll have to get there eventually
Which he almost certainly will. There are very few all-time talents in any sport that don't have at least one championship.
And if he doesn't? Any sane fair person should be able to evaluate his legacy based on the facts.
Barry Sanders is perhaps the pinnacle of an example of a player who is an all-time legend at his position that had virtually no team success. He didn't retire with any major records, he was on team that played 6 playoff games during his tenure, finished with a below .500 record cumulatively in the regular season, and he was really only great in a lone playoff game.
None of this keeps many people from ranking him as the best running back ever.
Different sport, different criteria for a RB than if an all-time QB retires ringless, but hey Marino fits that description too. In contention for one of the best QBs ever upon retirement, despite not winning the Super Bowl.
There are no real examples I can think of in hockey of a talent who played a significant amount of time and didn't see playoff success. I suppose Bourque and Hasek are the closest that spring to mind, players winning in the twilight of their careers. The Bourque storyline is beautiful and an iconic moment in the sport, but did him winning really change anything for him legacy wise? He would never be ranked ahead of Orr and he was top 2-3 before the Cup and remains so to this day.
I've read plenty of your posts to know you are logical and knowledgeable and that you're not really saying you'd let a lack of a Cup affect your own rankings, but it needs to be stated that lack of championships is not the death knell for a player's legacy that it's made out to be.