The most effective and insightful critics of a thing are the ones who love that thing (e.g. a good theater critic loves theater)

That doesn’t really apply to a system that’s corrupt by design, though. All of the people who love the political system the most are the same ones that benefit from the corrupt status quo persisting.

If you don’t love your society in spite of all of its flaws, then you aren’t in the right headspace to contribute to fixing it. You can’t be trusted to do so with care.

Loving the society/country in general ≠ loving the political system. A great example would be patriots like Michael Moore tirelessly working to expose the rot so that it can be fixed rather than continue to destroy the society/country.

You need someone who loves the country but hates the corruption of the system.