I think if you have a decent theory of politics, of the left-right spectrum, of the meaning of ‘conservatism’, ‘liberalism’, ‘socialism’, then neg. polarisation is a useful high-level ‘mapping’ tool. Doesn’t absolve you of digging into the detail, but it’s a good starting point.
This is an admission of low intelligence, from one of the most admired British conservatives of my lifetime.
Basically: “I hold my views on the basis of negative polarisation”. It’s like saying you oppose public ownership because marine le pen supports it. Daft.