With respect, I do not agree with the OP. for one fundamental reason. At any point in the game the player can effectively define the level of difficulty of the game. By simply changing the ship they fly. What the OP suggests would compel ALL players to equip their ships for PvP, and restrict them to eventually flying just the Big 4 "Endgame" ships, fully engineered to the hilt. But That I feel would kill Elite.
The whole ethos of Elite is "Play the game your own way", Blaze your own trail across the stars in any way and any ship you chose. If PvP is your thing then great, fly that Uber death dealing Corvette against similarly equipped death dealing monstrosities. If you feel that the CZ you are in is tame, park up your PvP ship and fly something that increases the challenge.
I, for instance, love my Courier. It is only partly engineered, mostly for speed. The shields are lightweight, the beam lasers and Guardian Plasma Charger are un-engineered. In the Ross 310 CG I have been driven out of multiple combat zones, lost the ship twice, gone head to head, 1v1 against corvettes aggro-ing them into chasing me either away from the combat area or luring them towards a group of allies. I would make 1 pass runs to distract an enemy so that the allied ship could turn the tables and chosen to engage fighters rather than high payout ships, to help out allied ships. Sometimes the fight was over in seconds, other times the battle would be minutes long. Sometimes I would win, sometimes I would "brave Sir Robin". Occasionally through teamwork, my allies and I could clear the CZ of enemy ships, driving them before us and reveling in the lamentations of their kinfolk.
I could have built a hyper-engineered Corvette and farmed a High risk CZ sweeping all before me. I could have farmed 10's of millions of credits in combat bonds with little or no risk. I chose to do the other thing, and probably had a lot more fun than the farmers.
Fly Safe Commanders and remember it's not about the credits, it's about having fun.