To be fair, I actually think it can be disrespectful, depending on the expectations that should have been laid out in session 0. While I haven't ever played in such a game, some people do feel very strongly that they expect their characters to have a meaningful story arc that won't be cut short by a random encounter. That's the whole purpose of session 0, and players who aren't comfortable with the game a DM plans to run should be comfortable not participating.
But in the end that's what this whole thing boils down to - respect between people playing the game. The legal argument is balderdash and poppycock, but respecting each other is extremely important! Be clear with expectations and treat each other with respect.