I agree.
"Made for playoffs" is hockey-speak for "we don't know why this better team is losing but we need to make something up to fill airtime."
You cannot kick butt as much as Tampa did during the regular season and not be "built for playoffs." Tampa ran roughshod over physical teams, fast teams, skilled teams, good teams, great teams, bad teams all season long. Playoff games are tougher but it's not anything you haven't faced before in the regular season. Plenty of super tough teams played in 82 games.
This is bad luck + injuries to their 1D d-man + their goalie going cold and CBJ's goalie going hot.
Bobrovsky has won Vezinas. His rep as a playoff choker was undeserved. Eventually he was going to show his regular season form in the playoffs. Goalies go hot and cold all the time. This is just the perfect storm of bad luck for Tampa.
I agree that 'made for playoffs' is meaningless. While I think injuries might play a factor, particularly to Hedman, every team in the NHL is nursing wounds by the time the playoffs roll around. But we can point to injuries, or goaltending being good or bad from either side, but there's still a trend of Presidents Trophy winners underachieving in the playoffs.
I think the biggest reason for this happening is that PT winners can be victims of their own success. Tampa has been steamrolling the league all season. I think there was an air of inevitability amongst certainly the fanbase, but perhaps even the team, that this was their year. It was fate. They'd taken their licks and learned from deep postseason runs that ended in failure. But they learned their lessons. And this year they hit the ground running and never looked back, dominating the league.
Then what happens? The playoffs come around and the intensity ramps up. This is playoff hockey, and many teams (especially the bubble teams like Columbus) have been in the playoff mindset for weeks, while Tampa just coasted to the postseason. Tampa is caught off guard, on their heels as they fall deeper into the hole. What's this? It's adversity, and it's the first time they've faced it this year. They don't know how to respond.
Best analogy I can think of is a fight between a house cat and a feral cat. That house cat can be bigger, better fed, better teeth, etc. But it won't match the ferocity and fight in the feral cat. And that's what this is. President Trophy winners spend the last month of the season worrying about things like resting up players, nursing injuries, etc. Bubble teams spend the last month fighting for their lives. And that's the mentality you need in the playoffs.
EDIT: Also in Tampa's specific case, you can't have your captain who is one of the best scorers in the league suddenly become a complementary (at best) scorer once the playoffs roll around. He's solidifying a reputation as a playoff choker and it's completely deserved. You need your best guys to be your best and the others to elevate their games. What's happened in Tampa is the opposite, their best guys have been no shows and no one else has stepped up.