A contrast with former times is that Virgin had experience from aviation, where you get a huge loss to the business if all the necessary staff are not all in place, or need replacing at considerable training cost if they quit, so you need to understand how worthwhile it is to look after them. In contrast the "bus bandits", as Roger Ford terms them, are used from upper management to dealing with staff of a more here today, gone tomorrow aspect, squeezed down to national minimum pay rate where possible, treated as expendable and readily replaceable, etc. It's a different corporate culture.
One reads here that staff have suddenly been told that holiday entitlements cannot be carried forward into the following winter months, and so everyone is using them up in December. For a business such as long distance rail that is a nonsense to do over the Christmas period, and should surely have been picked up by senior management before it happened. If you look at airlines you find very little leave allowed now, but considerable flexibility to have it generously at times of reduced demand.