I tried watching the 1980 show when it was broadcast, ... In retrospect, the thing seems entirely driven by money decisions,...
All was money decisions :
"Because letter writing campaigns in favor of restoring canceled television programs were uncommon in 1979, it prompted ABC to re-think their reasons for canceling the show. After some deliberation, they contacted Glen Larson to see about reviving the series, albeit in some modified and less-expensive format."
"This would allow them to weed out many supporting characters who were now considered superfluous - Colonel Tigh, Athena, Cassiopea, Boxey, etc. - which would bring down production costs."
In 1999, there was a good project for restart the Galactica show, based on the end of the 1978 show and having several of the original actor... a trailer was released... can be see at http://www.youtube.com/watch?v=gQNk6VMg9xs ... First episode was already filmed ( 40 minutes, never released )... fan have like very much the trailer but Universal have refuse it since they was already busy with a other project, the re-imagined Battlestar Galactica from Ronald D Moore...