SoDs are the non-hit point style of D&D combat. In a sense they are, like criticals, more realistic, because hit points are very unrealistic.
Setting aside the D, and concentrating on the SoD, it's an issue of the swinginess of combat. SoDs are, like critical hits, and high damage attacks in general, very swingy. Gygax's argument against critical hits in the 1e DMG, that they remove the player's capacity to make an informed decision, applies also to SoDs.
Pre-3e has a mix of swingy (SoD, low level combat, high level combat) and non-swingy (mid-level). 3e combat is very swingy with crits, SoDs and high damage attacks. If a grappling monster gets you, you're toast. Unless you had a Freedom of Movement in which case you're fine. Winning initiative is very important. It's very binary. Swingy and binary are, I think, the same concept. 4e goes the opposite direction from 3e and removes all swinginess. No SoDs, damage is low compared to hit points. You always die slow. You see it coming.
Swingy has its advantages. I've enjoyed, as a player, my PC's life depending on a single die roll. It's exciting. Swingy combats are less predictable, more thrilling. But PCs will die more often. As has been said upthread, that's fine if you have measures in place to deal - multiple PCs and/or henchmen, quick char gen, raise dead, etc.