This is not PvP, this is PK. And yes, you should be able to protect yourself. It is quite easy in tombruns, if there are not only noobs in party.
There are some weird people fighting 90 vs 20 lvl in full game, I don’t understand them. But if it is 1x30 lvl vs 7x25 lvl, you definetely can fight back. It is fun and you can check if there is somebody you can rely on and fight side by side with you, or your party is full of selfish cowards. This is how I make friends in D2.