They'd be risking it regardless, since the system being talked about does not 'see' players or NPCs, just encounters.
Or is it because you'd have to actually consider ship builds inconveniencing you? Its only a risk if you make it one- build carefully and fly skillfully and you'll be racking up money while the NPC and player attackers lose.
Currently, we don't risk it regardless, we fly the builds we want and enjoy our time how we want and get paid the same in any mode - which is what we paid for when we bought the game. The choice of engaging in PvP or not. And if we choose to PvP, we fly the ship we want for that task.
Forcing people into Open mode removes the choice and places all risks squarely on the shoulders of the "victim". As the attacker was already choosing PvP and had no risk (or "inconvenience") at all in their actions.
Now if a failed interdiction leads to the attacking ship being instantly sent to the rebuy screen, plus there were modules (or an FSD or engine type) a hauler could fit to assist them in the interdiction. Then the "inconvenience" is a bit more balanced out and the attacking ship is risking something.
But as it stands, the attacker has zero risk and all rewards. So due to that game imbalance, I'm not engaging in your one-sided PvP