£30 million between over 60 million people is about 50 pence each. Yes, I know they are not all taxpayers, but for even a largish family it would only be a few pounds (what one might easily spend out for a couple of pints in a pub plus a packet of crisps).
The police and soldiers may have earned a bit of overtime on top of their usual wages, but they might get the same for policing large sports events and there isn't an outcry over that.
It made a change to not have the news filled with school shootings, bombings, serious accidents/aircrashes etc. for a day.