[dfan]

I assume the following quote was not meant to be precise:

> The students didn’t even distribute the keys among themselves in a plausible manner. Each student chose an easy key to practice, so there were a lot of F majors and E minors, but no B flat minors or B majors.

but B major is pretty much the easiest scale to play on the piano there is!

[tomsmeding]

In terms of fingering if you know it. It's also one of the least common; there's a lot of music in F major, there's less accidentals in the scale and hence music in the key is more easily readable, chords are more easily deduced (less black keys involved), etc.