Scorch has one major use case: Base Race. Red is built as the colour which has the option to go all in early, and just send everything at the base to finish the game before your opponent stabilises and punishes you for going down so many cards. Usually, you can pretty easily knock your opponent down to 5-6 hp, but getting that last bit of damage can be hard. This is where Scorch shines.
As an example, look at this game. FrozenStorm misplayed in workering Scorch on T2 (even though he'd decided to base race). If he'd workered Musketeer instead, he'd have had the win on T5.
As a general play, yes it's worse than Deteriorate (this isn't saying much - if I were going to nerf the black starter making Deteriorate cost 1 would be top of my list of changes). But it doesn't necessarily lose board presence, you can kill a patroller with it, and on occasions it's a good trade (I think my most recent time casting it was against a Bloodrage Ogre in Elite: I went down 1g on my opponent, but the tempo was worth it).
That's basically my point: any card which is being played probably doesn't need a nerf. Both Musketeer and Scorch see play, and (for Scorch particularly) sometimes win games. Show me a game between two good players where Bloodburn was played...