http://www.librarising.com/astrology/celebs/images2/J/johntravolta1.jpg

In your own opinion, did the explosion of John Travoltamania help or eventually hurt 'Welcome Back Kotter?'

It helped....... Only because he was the break out star. All the girls were loving him back then in the 70's.

It was both. Early on it was a blessing because it drew in a lot of viewers and helped the ratings. Later, when John left the show it became a curse because the show suddenly found itself without it's most popular character and no matter how they chose to deal with it the fans would be unhappy.

Do you think the show should've ended once he decided to leave?

Do you think the show should've ended once he decided to leave?
I think the show might have survived but when Gabe Kaplan was reduced to making Cameos, the show was over.

Looking back it was the right move for Travolta to leave the show, though it really did decimate the show. Had they provided a suitable replacement (which would have been very difficult) it might have survived, but as Sonny said, with the diminished role of Kaplan as well, the others really couldn't pick up the slack.

For Travolta, though, he might have left at just the right time. The movies were calling and if he'd begged off till the end of the show (which, let's face it, the show probably wouldn't have lasted much past five years or so anyway), his chance might have been gone and he WOULD have been typecast as "Vinnie". It's really a case of a show burning VERY hot for a very short period of time (3 years), then just fizzling out into virtually nothing.