I can assure you that as someone that has done a couple Gov-related public-sites, some developers do think about it, and use suitable tools to ensure there's no issues.
Before the last-and-stolen-passports site went live (that I spent most of 2014 getting live - not writing - but mostly trying to get deployed), we did have a conversation, and easily proved that people called Mr or Mrs Null and/or O'Brien would have no problems. That conversation was also somewhat prompted by the Dartford Crossing site that went live a little before us - which had 'some issues'.
Before the last-and-stolen-passports site went live (that I spent most of 2014 getting live - not writing - but mostly trying to get deployed), we did have a conversation, and easily proved that people called Mr or Mrs Null and/or O'Brien would have no problems. That conversation was also somewhat prompted by the Dartford Crossing site that went live a little before us - which had 'some issues'.