Radical indeed, NJ, and almost identical to what Nigel Farage said recently about a bye-election. He claimed that it had all happened too quickly and that electors had no opportunity to study party policies and decide on which were truly closest to their own hearts.
The point, however, is - as you say yourself - virtually no one actually does this and consequently they just WILL vote for the local candidate whose success increases the chances of the Big Beast they want to see in No 10. In other words they do vote, albeit 'by proxy' as it were, for the Prime Minister.