Almost wrote:
Being able to play out of the ordinary maps is a skill of it's own and most people nowadays don't practice those sorts of maps any more since all people care about any more is being able to play fast.
The good thing about osu! is that great players are all-round players. I've yet to see a top-50 player who is extremely good at one thing but fails horribly in another area if you exclude mods (because there are some people who strictly practice one mod). They're either moderately-good at everything, great at everything, or amazing at everything; with few discrepancies.
I would be thoroughly disappointed if there's a top-50 player who can jump but can't stream, or who can read ar9 jumps but can't aim, or who can stream fast with low accuracy.
Let's rephrase that - luck for different mapping styles should not be a determining factor of skill in this game. If you have to use luck to finish these maps because you're so used to new maps, speeds or w/e, then you're probably doing it wrong. Don't call yourself good at this game just because you can play a select few mapping styles.