I'll answer in two ways. First, if there are both subjective and objective components to an evaluation, the overall evaluation must be considered subjective. Only a completely objective analysis can be viewed as objective.

Second, I'll use an argument I made earlier in the subjective/objective thread. It's mathematical but hopefully still useful. There are many metrics or criteria with which people can evaluate music. For simplicity, let's imagine 3 - innovation, melody, and funkiness. Again, there are many more, and some may be considered more important, but my argument would be the same if we included all of them. To compare works and conclude one is better, one must essentially calculate a value we can use for comparison, perhaps called its Greatness, G (one could call it lots of things, but hopefully calling it Greatness will not be problematic). To calculate G we would use the equation (assumed linear for simplicity):

G = a*innovation + b*melody + c*funkiness (or G = a*I + b*M + c*F)

We would then evaluate the works based on innovation, melody, and funkiness. It's possible that someone could create an objective method for assessing innovation, but I doubt everyone would agree on its merit, and subjectivity starts to creep in. I'm pretty certain no one would argue that melody or funkiness could be assessed objectively. So we are left with subjective assessment of the values for I, M, and F. But let's assume that somehow everyone agrees perfectly on assessing those factors, and somehow, they develop what everyone also agrees is an objective valuation. The real problem is the weighting constants a, b, and c. These essentially determine how important are the individual factors in the overall evaluation. Is innovation twice as important as melody? Is funkiness remotely important? If one asks 10 people or even 10 experts, I think it's likely one would get 10 different answers especially if the number of factors were increased to be more inclusive.

Any evaluation of works will include subjectivity on which factors to include, subjectivity on how to evaluate those factors, and subjectivity on how to weight the factors. For example, I have said for a long time that Beethoven's 9th is my favorite work and the "greatest" work of music. But my friend, Monty, thinks Parliament's P-Funk is better. I would assess the innovation and melody (and other factors) for the 9th and Monty would do the same for P-Funk. Monty actually thinks the 9th scores very high on I and M but rather low on F. P-Funk scores modestly on I and M but very, very high on F. The difference is that my weighting factors are all roughly equal; whereas, Monty's are a = .001, b = .001, and c = .998 (i.e. it's all about funkiness). When he evaluates the works, P-Funk easily beats the 9th. It's difficult to say why he's wrong because it's his evaluation based on what matters to him.