not wrong or really intentional as much as the fact that it just works that way. A 15 person vehicle can fit inside a 6 person ship purely die to weight/volume. Its hard to limit docking based on passenger capacity.
Problem is that having to calculate the weight all the way through the nested dolls would take a large amount of processing power (at least the way coders explained it years ago when it was brought up then).
The game would have to search the outermost entity to see what it holds, then search each of those and so on all the way down. SO if you have a toolkit in a backpack in a locker in a vehicle inside a larger vehicle inside a ship inside a larger ship inside a station, that is a lot for it to search and get the final weight from.
Just a matter of not having the processing power to pull it off for every single tiny little item in every single container in every single ship. Which is reasonable enough. I'm assuming that'd mean they have the coding ready and in hand, just not the right hardware and/or software.
I doubt they have code ready for it. What real purpose would it serve? It doesn't help anybody.
Passenger capacity is the main problem that exists for this scenario, not w/v. If you look at the vast majority of ships & items, their w/v exceeds their w/v capacity. So if you fill up said item the weight & volume are theoreticlly already accounted for. There are a few items that are different based on other specific stats and could be changed eventually, but at the moment most of the w/v is covered by the container having a larger w/v than its capacity.