There are also people in America who think not bombing the railways could have been a bad move, check out the United States Holocaust Museum webpage under an article entitled "The US and the Holocaust" here is the link:
http://www.ushmm.org/wlc/en/
and a selected paragraph:
By the spring of 1944, the Allies knew of the gassings at Auschwitz-Birkenau. Jewish leaders pleaded unsuccessfully with the U.S. government to bomb the gas chambers and railways leading to the camp. From August 20 to September 13, 1944, the U.S. Air Force bombed the Auschwitz-Monowitz industrial complex, less than five miles from the gas chambers in Birkenau. However, the U.S. maintained its policy of non-involvement in rescue, and bombed neither the gas chambers nor the railways used to transport prisoners.