Well, sort of. My trade ships have always been robust enough to survive a few shots. And then a few more shots for good measure to ensure that I can escape with full cargo without being disabled.
But thats sensible precautions though. A lot of traders fly the bare minimum (at NPC level).
A shield-hull balance much more in favour of hull would have been needed across the board.
Trader hulls were upped not so long ago, but it should have been that way (as well as delicate thrusters) to make it so its easy to disable- and that repair was also possible at the same time for those who were disabled.
This assumes that everyone only does one thing, though. Trade to get money, pirate to spend it, would become the approach. Piracy and hunting need to be profitable professions in their own right.
If traders had to venture into pirate space to score big, then you'd have that specialisation- i.e, dangerous places ramp up the profit (and set natural places to pirate). The scores come to the pirates, driven by the BGS / CGs. Its a better place than now where everyone mines to make money, gets top end ships with unending rebuys, and ganks in them because they are disposable.
Piracy shouldn't need to rely on the trader voluntarily pressing the "dump cargo" button. The mechanics would need to be set up so that:
- trader is trying to escape and will probably succeed in doing so with their ship (mostly) intact
- pirate is trying to blast a large enough chunk out of them to release plenty of cargo before they do
Indeed, its what was wrong to begin with- stopping a trader was hitting engines but the hull went pop beforehand.
No need for comms beyond the implicit "You are being interdicted, this is a hostile act, prepare to fight or flee". Trader doesn't need to care whether this is a "pirate" or a "griefer" because from their point of view both will open fire and try to do large amounts of damage to their ship.
In an ideal world pirate tools would indicate intention, just as seeing a prowling FdL with an interdictor spells trouble. Seeing a pirate with cytos, hatchbreakers etc is at least a sign its a pirate and not someone out to kill them for no reason- not that it stops people logging anyway.
The big catch with getting a pirate-trader ecosystem to work is that it also needs to work both ways in PvE. Player-player encounters are just generally rare, in most systems, so if the NPC pirates are pushovers then it doesn't really matter what the player pirates try to do. That would be the really big change - if traders expected to take some losses to piracy (in the same way that bounty hunters expect to pay a bit for ammunition) as part of the career, then it might be workable.
NPCs don't work throughout the game anyway

As you know NPCs are window dressing for the abstracted BGS. The biggest change would be having NPCs that are actually outfitted to be pirates- cytos, hatchbreakers etc, fast ships and are prevalent all over based on sec level (much more than now, surrounding stations etc for a sneaky theft, that is, if drop zones were pathetically short, another mistake).
It's obviously far too late to change Elite Dangerous to being that, and given the role of pirates in previous Elite games I'm not sure it'd necessarily look much like an Elite sequel if they had (because "armed trader fighting off under-equipped pirates" is so much of an archetype)
Its far too late sadly, which is a shame. The problem is under equipping and making credits scarce drives innovation, guile and teamwork. Pirates should be parasites that leech from greedy traders, the median pirate ship being something cheap to run and fuel (and fast).