Flame strike was an AD&D spell for clerics just like fireball. And it was cleric only. Sadly it didn’t get the same “legacy” treatment. It wasn’t as iconic as fireball but at least when I played AD&D it was iconic cleric and a go to spell. I don’t have access to my 1E books at the moment so I can’t say how it compared back then.
In 2nd it was 6d8 save for half and a 5 ft. radius on 30 ft. column.
In 2nd it was 6d8 save for half and a 5 ft. radius on 30 ft. column.
I mean that's not quite true. The real answer is "because It's a business decision, not a gameplay decision"