I wasn't the GM, but my thought is that he wanted to maintain some level of verisimilitude. Each time we started with a new group, we represented another dungeon faction.Sounds pretty OSR to me.
Is there a reason you couldn't start over with the same characters to save time? Play a zombie version of your dead character?
I guess I'm not the OSR type. I don't have nostalgia for this kind of play. I like the idea of lighter rules, thinking outside your character sheet. But I don't like throwing away characters after a single hit or save or die saving throw (we all died to a DC 15 petrification effect).
My "old school" was building theme and dread through clues and investigation. It was talking to the villagers and finding out that they were dealing with a werewolf. And since we were unable to fight it directly, we would research weaknesses, try to scare it off with torches at night while the silversmith fashioned a single silver arrowhead, then send the fighter out to grapple the beast so the ranger could shoot the arrow in its heart.
It wasn't a dungeon crawl avoiding room after room of goblins until we eventually failed a check, we got overwhelmed and were slaughtered. Then you laugh and make new characters. And you rinse and repeat for a year. If that had been my game, I'd have rather played Diablo or HeroQuest.