Star Wars hasn't gotten worse. It was good in the OT, took a hellacious nose dive in the PT but The Clone Wars is bringing it back up.
Star Trek had a similar, if less dramatic, trajectory. TOS, TNG, DS9: creatively strong. VOY and ENT: big step down. Trek XI: back up on top.
The real difference is financial. Star Wars has always been highly successful, regardless of how bad.
I'm interested in the numbers, too. Can anyone possible compare all Star Trek related revenue (TV, MOVIE, Merchandise, Conventions. etc.) to all Star Wars related revenue.
Since I can get the movie numbers easily, I'll post those. All numbers are domestic box offices taken from boxofficemojo.
6 Star Wars Movies:
episode IV - $460 MM
episode V - $290MM
episode VI - $309MM
episode I - $431MM
episode II - $310MM
episode III - $380MM
Total - $2,180MM
11 Star Trek Movies:
XI - $257MM
X - $43MM
IX - $70MM
VIII - $92MM
VII - $75MM
VI - $96MM
V - $52MM
IV - $109MM
III - $76MM
II - $78MM
I - $82MM
Total - $1,030MM
Obviously, in movie dollars, its not even close. SW blows ST out of the water.
Now can someone else find and post the TV dollars?