Interdiction is super weak sauce... and only applicable in the bubble and only when carrying cargo (mostly). It does nothing for exploration. I would not consider it much of a solution. Nor is gravity wells. Space is big. The chance that other objects will be in your way is small and most at best, simply slow you down for a few seconds. There's no piloting skill needed to supercruise. No real scale between pro supercruisers and new players once they figure out the 6 second rule.
Yes, interdiction was mostly in the bubble, but cargo wasn't needed to trigger it. For me that made it annoying when I was exploring and had no cargo and the pirate messaged in SC "What a nice haul. Surprised you made it this far." or "The rumors were right about you."
The over engineered gankers pushed the "submit and run" which made the "casual players" demand changes instead of them having to develop the skills to see when they were being stalked and take action to make beating interdiction easier and the flying skill to do it.
If interdiction is a problem for anyone, go here to see how to make it just a normal part of the game..
Now, yes, interdiction does seems to be triggered when you have cargo.
BUT
Cargo mined where there were no pirates or salvaged cargo where there were no observers SHOULD never have been a "trigger" since there is no way that the pirates could know you are carrying anything.
NOW, cargo bought at a station is a completely different matter. Especially if it is mission related cargo. NOW the pirates could indeed know you have something.