Why use his career average? It's not like he's put up around the same number of points since he entered the league. His first few seasons are not why he got that contract.
He's at .67 PPG this season (Nevermind that he's also a -12 and half his points are on the PP).
The previous four seasons his PPG were .76, .76, .73 and .72. It's a small sample size, but it is also a significant drop. It is not made up.
I don't know if he's streakier or not overall but prior to his injury, he had 1 goal in 20 games.
And it goes beyond points. You can't quantify his disappearing act by points. Players often factor in games without showing up on the scoresheet. There's so many games that go by where you don't even notice Franzen, and that shouldn't happen with someone of his talent. Guys like Sheahan and Tatar regularly factor into games more than Mule, even when they don't score.
He's scoring at .67 ppg despite a pretty big slump (as you point out). He's gone through those before. Nothing about his play this year led me to believe that he wouldn't end with right around 55 pts. Which is usual for him. I dont' see some big, qualitative difference in his play. He was doing what he does every year.
I agree, lots of people factor into games even when they don't score. Those guys are better than Franzen. And it's because of those guys that he's no longer necessary. But he is what he's always been. The only difference between then and now is that we no longer rely on him as much. But quite a lot of people here have said, or implied, that his performance is worse this year than in years past. I just don't see it. If Nyquist and Tatar (and Abby to a lesser extent) hadn't emerged into go-to guys, Franzen would have been glued to Zetterberg or Datsyuk's wing like he always is, and his PPG probably wouldn't even have dipped at all.