In their defence Bombardier has transferred ownership of the Q400 to a new entity, so that wont have helped. Eastern have recalled a wet-lease E-190 from TAP to cover their unavailable fleet. FlyBe are (by all accounts) a new airline so delays are quite common and their fleet ramp-up was ambitious. That is before difficulties recruiting and getting security checks for crew are taken into account.
I think a few things have happened all at once, rather than one single disaster as flyBe are trying to spin.