Sure, they help contribute to long playoff runs, but even so... no one pays to see those guys.
The superstars are the reason tickets get sold even when the team is losing.
Another reason why the lion's share of a team's salary should go to the superstars.

I mean, seriously, if your best argument is that 3rd and 4th liners demand good money because championships can't be won without them... then what should 3rd and 4th liners from losing teams get paid? League minimum?!
Ok then.

Sidenote: Chicago also struggled to make the playoffs because their goaltending fell apart. But again, it doesn't matter. Fans pay to see Pat Kane, not Adam Burish. And they continued to pay to see Pat Kane even after Chicago fell from grace.