I do not know how to interpret your reasoning Cooky, everyone is free to have their own favourite... To quote what Ross said, "It is not disrespectful just because someone voices their option that they like someone over another." All you do is placing your vote in who is your personal favorite, I really see nothing wrong with that.
For example, the question was not: who is the worst GM of them all? That would be wrong.
I suppose that in this poll, people most likely voted for Mater because he treats players in a friendly way, he is also very talkative which is a great expertise to have. Then there are other GM's who are working better in 'other fields' and for other tasks. They are all useful for the server which is the principal. However, Mater definitely deserves the votes he gets just as much as they all do.
Personally I did not vote, I believe they complement each other in a decent way. In other words, they possess own abilities and characteristics to be functional as a group. They are good in their own way and overall nobody is better than the other one, imo. Some may be more active than the others intermittently but that is just something inevitable.