not following their own rules by letting people retake parts not only on day one but also day two and sim sessions
Quite simply it's down to supply and demand.
With changes to Bidline, pensions, pay-points and the work load that is SH and the associated freeze the company, using it's own processes, hasn't got the intake it requires.
Hence, adapt and overcome. Change the requirements, as set by the company itself, and look at alternatives.
At the end of the day it is your date of joining that sets your future in BA for just about everything, not which fleet you join on. You will be able to move eventually and then you take up the same position as if you had gone as a DEP except, perhaps, without the years of being at the bottom.
That's how I've always seen it, see it however you will.