because it was the 60's and they had not enough funds as rodenberry had to pay the cage and where no man has gone before out of his small savings and the small amount of air time he got from NBC which only allowed for 1 hour of aired footage per program.
They were still unsure of the "Wagon Train to the Stars" concept. And, in the end, "The Cage" and "Where No Man Has Gone Before" did add up to feature-length. What was extraordinary was that the studio and the network even ordered a second pilot. ProfessorTrek 03:35, July 1, 2011 (UTC)
Also note that niether of these episodes were used as televised pilots in the modern sense, They were produced to be greenlit by the NBC executives, with the intention of later repurposing them into episodes should the series be accepted, "The Cage" was not publicly broadcast in it's original format (aside from scenes used in "Menagerie") until many years after Star Trek went into syndication, and "Where no man has gone before" was aired after "The man trap" and "Charlie X"
The later series pilots, such as "Encounter at Farpoint" were feature length because the series were already greenlit by the network and they were written as long episodes in order to sell them to the fans.-Cpthunt 04:59, July 1, 2011 (UTC)