To be honest, it is the second-highest-charting sorcery, and thats something
Edit: To expand a little bit, I collect vintage 1st Editions myself and I only collected thick stamp Base Set cards so that all my stamps would be uniform
This effect is primarily blue, but appears across every color with different restrictions or costs
If you're running full-on mono-Red, this card can be a very powerful part of the top end of a burn-heavy Big Red deck, and might often very well either put an opponent to death, or put them nearly to death while mopping up the table
Turn to Slag can target a creature that has no Equipment attached to it
That feeling matters when evaluating why the charizard pokemon card retained relevance long after many early cards faded into obscurity