User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-5089728-20120918015409/@comment-4563270-20120918041919

there may be a few reasons for this... downloadable demos on 3ds are acheivable through the newer nintendo network they have made but have yet to fully impliment as wiiu has not been released but mh3g was being made long before we heard high or hey of demos or the N network discussed as the miiverse for wiiu. In order for capcom to have run internet connections for the 3ds would require them to run their own servers when games like mh3 and mhp3rd are still in use. Had capcom made mh3g at the same time nintendo was tempering with their new network they could have had nintendo managing it FOR them.

Now with an improved port and overhaul for the wiiu they can EASILY utilize the internet infrastructure on the wiiu for local internet on mh3u and seeing as how mh3u has been quoted as being "mh3g" it stands to reason that mh3u on 3ds is not made for the network either and would require more work to do so in more ways then an online update but a reconfig of the software too.