"Slaughter PCs left and right" wasn't serious and it was a bit of an exaggeration, sorry if it came off as serious. But from what you stated, if death isn't regularly on the table it's frustrating to you. But there is no way that every DM will be a perfect fit for every player and vice versa. As DMs we always have to decide where to draw the line and where to compromise. If you don't want to run a game where permanent PC death is rare you should tell that to potential players.
The important thing is that you discuss various aspects of the game ahead of time. I include things in my invite to new players, my restrictions and what kind of game I run, so they have a decent idea before they even join. So that means that if a player wants to run an evil PC, I'm not the right DM for them. For some people replacing a PC isn't as simple as "
just make another one"(
1) and if you want to have a higher lethality game like
@Lanefan (more power to them, I don't think I'd want them as a long term DM), then you have to be up front with players about it. That may mean you have difficulty finding players or have current players who don't want to play in your game in which case you have to decide what's most important to you.
I tell people up front that death is never completely off the table in my game and we go from there when discussing how lethal we want the game to be. But it's up to you to set what your expectations are and up to the players to decide if they're okay with it. As always, my advice is to have a frank and open discussion with players offline or outside of the game session if something isn't working for you and try to work it out. But personally? I just accept that I'm not going to be the right DM for everyone.