1) He wants to go to this system
2) He doesnt want to dump his cargo
3) He doesnt want to BH in his current ship
Its a bit like complaining you are locked in your room because you want to swim in your pool but its dirty, and you dont want to clean it.
To be fair I was a little annoyed about being "locked in my room" as you say since it was an investment and long journey to get to the holiday resort and find it's not as advertised hence a little ranty. However you've missed my original point - in your analogy I WANT to clean the pool, but I'm not allowed to use the changing rooms because there's no lockers to hold my kit bag.
My main point was that I don't see why I cannot change my ship. If you can store modules you should be able to store cargo, or at least leave it in the ship that's currently holding it. You simply cannot go bounty hunting in a cargo vessel and expect any reasonable chance of survival.
It's not about the fact there is a thing called lockdown. I get that and support it. What I don't get is that presumably when you switch to another ship your original vessel is going to be sitting in a garage with nobody aboard. It makes no difference to the station whether that vessel contains cargo or not.
I don't know why it's not done in the Elite universe, maybe Frontier are worried about some kind of commodity loophole or something like that...
At the end of the day, I appreciate the suggestions of checking the status of the station prior to setting off (which is no use on long trips where the status may change en route) or simply going somewhere else and selling the cargo, or by dumping it into space (whoever came up with that must've won the Lave lottery and not care about space cash) but in reality what would you do if it was a real situation with millions of credits worth of cargo destined for a community goal? If you had a spare combat vessel you'd lock up your ship, jump into your fighter and go bounty hunting to bring the lock down to an end quicker.
Hell, the station could even charge rent for storage space - not sure why this isn't already done for empty ships sitting in garages since presumably they're taking up space and maybe power.