If you read the comments at the bottom of the YouTube video it becomes even scarier, with almost all of them questioning how one of their favourite songs of all time has landed up in a "worst songs" list.I think he was singing the notes like playing darts - missing most of them and getting accidentally close to the bullseye only on occasions.
You do have to understand, however, how huge Nick Berry (and Eastenders more generally) was in mid-1980s Britain. That song literally was the soundtrack to a lot of people's lives back then, in the days when there was no internet, no streaming platforms, and we all watched the same three or four commercial channels, at the time the programme was broadcast (not at a time of our choosing), and how at school the next day (or round the water cooler if we were working), we all talked about the same stuff we'd watched the night before.
Back then, mainstream media was what connected us to each other. Nowadays media (mainstream, splintered, fringe, obscure) is what pushes us apart, or at least fragments us.