The result was no consensus. Consensus leans towards deletion, but various solutions have been suggested that would rectify the problems raised here without wholesale deletion of the article - possibly involving cutting it down and merging info elsewhere. There is sufficient argument in favour of this path that I do not think a consensus to delete has yet been established. I would recommend a renomination of this article in the intermediate future if the unmaintainability and navigability problems remain unsolved. ~ mazca talk 13:52, 9 August 2009 (UTC) reply
In short, this single list is too unmaintanable, and has been replaced by lists by state.
It has about 2000 railroads listed. I just finished redoing the pages listed on Template:US railroad lists for all 50 states and D.C., listing all defunct railroads I could find; the total number is over 10,000 railroads. In addition, about half of the companies on list of defunct United States railroads didn't actually build or operate anything; they were just chartered and left to die, and should not be listed. (I checked each one that was on that list but not on one of the state lists, and got under 20 that needed to be added to the state lists.)
This has also been discussed a bit at Wikipedia talk:WikiProject Trains/Archive: 2008, 4#List of defunct United States railroads.
In other words, the state lists are much easier to maintain and have better information. NE2 16:28, 1 August 2009 (UTC) reply