It's a open game with no rules to how you can play. If it's not cheating/exploiting than anything goes for the most part, only a very few methods of griefing have gotten people banned.
It's not a PvP game but there is NOTHING stopping me from going around and killing every commander I see. It would be taboo, it would garner me quite a bit of hate, but there is not a single thing stopping me until other CMDR's force me to stop.
BTW, I am not killing Commanders, the only time I get involved in PvP is powerplay or when I hear about CMDR's pirating other CMDR's. But I am saying that this game really has no "rules" so saying it's not a PvP game is like saying "It's not a mining game, it's not a trading game, it's not a combat game". The game supports those activities and allows them, it's true that PvP has little incentive outside of Powerplay (and even there it's rare) but it's in the game and it's allowed, so pilots can do it if they want.
Also wish people would stop saying "ganking", what are you expecting a fair fight for? You can see people coming on the Radar, and even if your in a type 9, rigging a ship up to escape a interdiction isn't hard. There is a quote by Steinbeck that sums it up.
“If you find yourself in a fair fight, your tactics suck.”― Steinbeck John
If you decide to fly with crappy shields and no defenses in the name of more cargo space, the possible consequences are on you. I have been interdicted by 3-4 man wings plenty of times doing CG's and escaped every time.
TLDR: It's not sold a PvP game. But PvP is a option in the game for players to choose. Getting upset because other CMDR"s decided they wanted your cargo or wanted you dead and weren't going to be honorable about it isn't going to change anything. If the concept if getting attacked by a player is too scary, Solo is a option.