Well, that makes a little more sense, in the same vein as Dusknoir getting Mega Kick because Dusclops got the move from the Generation III tutor. But still, they give it to Fearow, but not Dodrio? And they give it to Beedrill, but not Escavalier?Drill Run was pretty much only given to Pokemon with drill-like horns. For example:
Forretress only gets Drill Run because Pineco does--generally, tutor move compatibility extends across entire families in BW2.
EDIT: Serebii's revealed by how much the Shiny Charm increases the odds of finding Shinies.
The Shiny Charm cuts chances of normal shinies to 33% making the chance 1 in 2370.6recurring standard.
If you're trying to Masuda Method it, then the chance has been reduced, but as dramatically. It has gone from 1 in 1365.3recurring to 1 in 1024.