I disagree.

The complaint was that a grant from the government makes the press less free to criticise the government.

If the grant is clearly and legally bound to be determined according to a set of objective and publicly available metrics I do not see that it would be such a big problem.

Of course a vindictive government could do what they can to negatively affect the press outlet in question but similarly could a supporting public affect them.

In any case it can all be accounted and prepared for as long as the process is objective and transparent.

The selection of arbitrary objective metrics and the weight associated to them is subjective by nature. Every ranking system is subjective by definition even if the outcomes are measured objectively. Every ranking system is by definition mathematical garbage that we use to evaluate whatever we feel the need to evaluate. We still need them as filters and for other reasons.