Diablo

The game is supposed to be an ominous and foreboding ARPG, and instead I run across BgButzzzz6nine, or I start moving towards some creatures on the other side of my screen, and before I've taken two steps some Necromancer and undead horde come buzzsawing through the area like a scythe, and I have to try and find someplace where I can actually kill things. The isolated feel was a key point of the game, and added to the ambiance and feel of the game. Now, I can't go 2 minutes without getting that immersion ruined by some random intrusion by another player. Is there some way to not be surrounded by other people while playing the game?