Earlier quoted context omitted.
You're 100% right. The UK would be served just as well by a nonpartisan president.
> nonpartisan president Oxymoron. You have to vote for a president right otherwise you end up with ... well Oliver Cromwell. A Dictator by any other name.
Nonpartisan in the sense that the Queen is nonpartisan. So of course, partisan. Still, nonpartisan like not publicly wading into political debates, and not opening up the office to the vulgarities of electoral politics.
For example, Germany elects its president by convening both the Federal and State legislatures together, who then vote. By pulling in all the regional parties and legislators, the President has to have broad support across party lines. It's also convention that the President doesn't wade into daily political issues. The result is a largely ceremonial office, usually held by a broadly respected statesperson with former government experience. Which is what you want for the "emergency button" you hope you don't have to push in the first place.