I just don't really agree with the Idea the a POTM winner could just choose their friend's game instead of one that is truly POTM material
On the contrary, I believe even more of the "choosing friend's game" would be the case for voting. Voting, as anonymously implemented, gives no actual pressure in the outcome on an identifiable individual. Hence, people are completely free to choose without discrimination of any kind; which allows the tempting choice of friends; or socially well-known individuals among the forum.
On the other hand, when choosen by one person, it is publicly known that the choice is presented by the individual; hence it is heavily subconsciously questioned whether the choice is viable material or not. Under such public pressure, the individual is forced to choose one that upstands to the quality.
However, there are certain major flaws in the choice of one person as well. But in most cases, they are matched with the same sides to that of voting's (e.g. genre discrimination; RPG community = RPG oriented). But none the less, I believe that the following month's choice is an obvious one in terms of cross-genre comparison judging by the work put to it and its presentation as a whole.