Maybe, however the IATA standard cabin bag size is 56 x 45 x 25 *including wheels*. My usual cabin bag is exactly 56 cm including the wheels and so accepted by Easyjet and most others.
FlyBe however has (rather sneakily in my opinion) reduced its allowance by 1 cm to 55 cm thereby ensuring the "standard" size bag such as mine and most others doesn't fit.This then adds an extra £14 per sector on top of what are already higher fares than their competitors.
That being said, as a pilot myself who has worked for another airline who failed to adapt in a ruthless and cut-throat market place (too little too late), I know the frustration the employees must be feeling!