"All their technology" probably involved 30-35 dumpsters with Jump drives and dirty air, food processing machinery that barely worked, and a battlestar that was broken into 500 pieces upon reaching Earth. They had very little technology worth keeping. They also wanted a fresh start and, over four years, managed to get over the lack of creature comforts of their own lives. Clean air and grass is a godsend for these people. It may not be "realistic" (the entire series is not realistic - battlestars and cylons?) but it is definitely believable.