In fairness...
Nintendo wouldn't want to release just English language versions of games in 60hz. If they were going to do it, they would want to support all major European languages. This is an issue because they probably won't sell many of them, and it would cost money to do this. In addition to some comments about fixing it, not all PAL games can simply be switched to 60hz without issues occurring (games with optimised sound would fuck up for example).
They won't release every VC in just 60hz either, despite a few occasions I can think of when they have (Metroid Prime 2, Zelda bonus discs, Sin and Punishment N64 VC). It's not possible for them to switch every game.
Also, ratings are probably an issue for them, with certain games getting rated different, content etc etc.
However...
Nintendo should just offer a 60hz English only option on the store. And, don't all VC games need to be re-rated anyway these days? I think they do, which is how we find out early about games coming out.
If F-Zero is 50hz only I'll email them again. I really want this game.