“Taxi” was in the Top Ten its first season, the ratings plunged after that and ABC kicked it to NBC for its final season. Did ABC execs not like the show?

Lots of reasons. Jeff Conaway got fired for drug use. Andy Kaufman was difficult and was holding up production. The storylines got stranger and stranger as the show went on. It went off the rails at some point and the audience tuned out. If it was making money, it would have stayed on the air.

Not all shows can last season after season. Netflix isn't even looking for such shows now. They want new things shown all the time. I guess that's what people want, too.

Other factors might've had to do with any lead-up changes done after the first season.

I vaguely recall the show having a 9:30 timeslot on Tuesdays...

Did the show have a regular timeslot? Or was it moved around? The show got better once they added Christopher Lloyd so it doesn't make sense that the ratings would go down from lack of quality after the first season.

Good comment by all the posters, let me give my take on this.

Taxi spent its first two seasons on the air tucked safely behind mega hit Three's Company on Tuesday nights. Three's Company was on at 9pm with Taxi at 9:30. Three's Company was the number 2 show in America both seasons. ABC felt comfortable moving the mature Taxi series to Wednesday nights at 9 pm behind another top 15 smash, Eight is Enough. This switch did not work well as a matter of fact the entire Wednesday line-up didn't work out well. Eight is Enough tanked after 4 successful seasons and was cancelled. Soap the show on at 9:30 had been a top 25 series, and Soap as well as the 10pm show (Vegas) also tanked and were cancelled as well.

With the entire Wednesday schedule with the exception of Taxi cancelled, the series was moved back to the 9:30 timeslot, but on a new night Thursday behind the hit series Barney Miller. As it turned out, Barney Miller was out of gas dropping to 54 in the ratings, in fact all the series between 8pm and 10pm (including Taxi) were not part of the ABC schedule for the follow-up season.

Taxi stayed in the 9:30 Thursday timeslot but on a new network NBC. Taxi was behind Cheers which was two seasons away from breaking out and becoming the landmark series it would become. That coupled with a stacked CBS line-up (Magnum PI, Simon and Simon and Knots Landing) helped doom the series.

Taxi was a very complicated series with a lot of moving parts, I loved the show, to me it's one of the best series ever, but audiences tend to like predictability in storylines and character interactions ,Taxi doesn't give the audience that. Greenbeans makes a valid point.

I want to make a final point about Jeff Conaway, there may have been too much talent and too many great characters for Conaway to have the kind of part he desired. I hate to say it but the show really didn't need him.