My personal opinion is this,
I think V-STEP have done a fantastic job with ship simulator, considering Ship Simulator is quite new. And i can understand the fact that they would be reluctant to allow people to add their ships into the game, look what happened to Virtual Sailor, lots of the user created content there to be honest is quite bad.
But i do think that if people come up with decent ships that are up to V-Step's standards then they should be put into the "Ship Yard" on the Official site, and i also think the same for the environments as well, and for any other bits of great content users can create, for example, Goax has made some fantastic ships for Ship Simulator, like the berge stahl and the Pushboat he has made, people like him should be taken seriously and i think V-STEP should hire someone like him to create ships, and other bits of content that could be downloaded in a patch (e.g. visible GPS's in the wheelhouse, oh and i don't mean the ships for free, just the little bits of content like the GPS in a patch).
I think that professional ship makers should be allowed to add their ships to the game, as long as they pass V-Step's standards. And that goes for any other content like environments and other things that could be added, like what i mentioned before, a visible GPS on the bridge.
Jack.