I spy a quote from one of my own posts there, Steven ;-)
Public holidays in this country have their origins in the days when the vast majority of the population were Christians. Even if they weren't, they were forced to comply (either by law or by convention) with the practices of the majority of the population.
So nobody ever questioned whether it was right or wrong to work on, say, Good Friday. It would have been regarded as heretical for anyone to do so. Similarly, religious tradition meant that nobody should be working on Whit Monday.
As the years have gone by, the religious significance of such holidays has become less important to the majority of the population, to the extent that 'Whit Monday' has now been replaced by the 'Late Spring Bank Holiday' and a completely non-religious holiday (although still with its roots in pre-Christian ceremonies) has been added to the annual list. (i.e. 'May Day').
Whatever else the advantages and disadvantage or organised religion might be,it does impose certain fixed practices upon the society which embraces it. (Simply look to certain Muslim countries if you don't believe me!). A largely secular society sees no obligations to fit in with such practices.
Mt own preference would be to simply abolish all public holidays (except, possibly, over the Christmas and New Year period). Of course I'm not suggesting that anyone's annual holiday entitlement should be reduced, simply that we no longer pretend to have everybody on holiday simultaneously (when clearly that isn't happening and when many people would rather have their holidays when they choose to, rather than when the Government says they have to).
Chris