But what would you rather have, an email marked as spam that wasn't, maybe causing you to miss an urgent message, or some spam allowed through? In my experience most people go for the latter.
How about anti-virus engines? Would you rather one prevented you installing a legitimate piece of software or occasionally let through something rogue? Again most people put up with the former, you can usually tell the anti-virus system that it made a mistake and override it when needed.
Both these instances show that, as the old saying goes, better safe than sorry. A slight inconvenience, seeing the odd spam email or having to re-enter credentials to allow an install, is preferable to missing an important meeting or letting some Moscow miscreant have all your bank details.
Why am I bringing this up? Because recently there was an outcry in the media that Prince Andrew had been challenged to identify himself by the security services as he was walking through the gardens of Buckingham Palace. Questions were asked such as surely they should have recognised him? Well who knows. At twilight from a distance you see a figure in the grounds, you are tasked to protect the royal family and recently someone has been arrested after climbing the palace walls. You can't quite make them out do you think I'll let them carry on, he looks a bit like Prince Andrew or I'd better just check?
What do you think is better, an occasional palace resident being asked to identify themselves or an assassin allowed to continue unchecked (republicans need not answer)? And if any guard is disciplined for challenging His Royal Highness then that increases the chances that next time a malefactor will proceed unhindered. So as to the force apologising to Andrew, forget it, he should be grateful that they are there.