Ganking is just overkill - in supercruise you can get an idea of the role of another Cmdr by looking at their list of modules, an activity I enjoy & do as part of the IFF process. A dedicated exploration build is usually easy to spot, plus a returning explorer may be a little out of practice but they also carry enormous BGS influencing potential that unlike most player activities is failrly easy to predict - they will be increasing the influence of the controlling faction of the station they are headed towards.
An explorer returning with a large amount of data, in a highly optimised (for jump range) ship, in open is a vulnerable and easy target with an effect of the BGS that can be predicted better than most. Stay on your toes.
In March I returned from an 18 month grand tour of the galaxy. I play in Open, I explore in Open (not saying much, the threat is vanishingly small), I entered Colonia for the first time in Open having no idea of the reception I would receive, and I returned to the bubble in Open carrying an enormous amount of BGS influence.
So I was careful. I chose my entry point and time carefully (I returned at about 2am local time), my ship was armed & armoured, I checked every ship in supercruise and I didn't fly straight from the star to the dock, I gave the shipping lanes a wide berth.
Later I used some of that data to re-take control of my home system at the time, which had been flipped while I was away. I didn't find out who I was competing against until one of their team came to investigate who had managed to flip one of 'their' systems back, but as it turned out I flipped a Hudson Controlled system - ie I singlehandedly managed a surprise victory against an entire powerplay player group. That's how much potential an explorer is carrying.
So someone might well want to prevent you from doing that. But others will want to help you. Most explorers don't care a jot about the BGS and are happy to sell their data to help a BGS playing friend if asked - that friend will be motivated to help you dock as much as another might be to kill you, and
that is the game I enjoy
Or just switch to solo.