Well, the point is that--for most shows and most people--the idea of jumping into a previously aired series requiring a 100+ hour commitment to work through is daunting, to put it mildly. Given the amount of TV hours I budget, I know it's a non-started for me; I still haven't made it all the way through the Sopranos. There are a lot of shows--even many with well-defined arcs--that lend themselves to a "20 hour version" or so approach capturing both the overall flow and feel of the series. I'm not sure it works for everything--not sure about BSG or Lost for example--but I think it works pretty well for most of Star Trek.