I don't think DCS has out grown itself, maybe it has out grown your monthly download allowance; did you know that GTA V is a 60Gb download!? Bigger downloads, faster broadband (more memory, faster graphics cards, processors, SSD's, the list goes on), it's all the future and unfortunately we all need to keep up.
Edit: Just had a look at my most recent purchases on Steam and to be honest they are all over 9Gb (Thief (24Gb), GTA V (62Gb), Skyrim (13Gb), Dragon Age (16Gb) and Metro: Last Light (10Gb)).