My analogy about Miles Davis wasn't referring merely to his technical ability. It was referring to him being a "good" musician. People . . . A LOT of people enjoy listening to his music and appreciate him for a lot more than the his finger dexterity. They listen to him for entertainment and are, presumably, actually entertained by him -- even if I'm not.
GTA shares a similar purpose in life -- to entertain. A LOT of people enjoy playing GTA. They appreciate it for more than it's ability to reproduce graphics and sound (both of which are pretty rudimentary, frankly). They play it for entertainment and are, presumably, actually entertained by it -- even if you're not.
In either case a subjective analysis would produce a bad review, the first one from me, the second one from you. However, by aggregating the subjective analyses of many different people you can use statistics to determine the likelihood of a game being enjoyed. You can determine it with pinpoint accuracy, that a person is, for example, 70% likely to enjoy a given title. A game with a 95% likelihood of entertaining any given person who plays it can legitimately be referred to as great compared to, say, a game that has a 5% likelihood of entertaining. There's absolutely nothing wrong with claiming that E.T. sucked, while Yars Revenge was fantastic.
Logic 101:
An inductive argument is one in which it is improbable (vs. impossible for deductive) that the conclusion be false given that the premises are true. Thus, a strong inductive argument is an inductive argument in which it is improbable that the conclusion be false given that the premises are true. In such arguments, the conclusion does in fact follow probably from the premises.
My argument in a nutshell:
Most people do not enjoy bad* games and enjoy good* games. Every iteration of Grand Theft Auto soars to the top of sales charts and remains there for a very long time. They go on to get near-unanimous excellent reviews (that you and I both know Rockstar doesn't pay for), while other games, including games that attempt to duplicate the gameplay format and violent themes, get extremely poor reviews. This suggests that Grand Theft Auto is, in fact, an entertaining, or high-quality game.
My argument is logically strong because given the truth of my premises, there is a high probability that my conclusion is true as well. It's also logically cogent because all of my premises are true. My own personal enjoyment of the game also did not enter into the argument, but rather it relied solely on statistics (this is where the objectivity comes in).
*The words "good" and "bad" are used here as they are most commonly used -- to refer to high and low quality. It is generally understood that a videogame's primary purpose is to entertain. The degree to which a game is successful at entertaining, then, corresponds to the games "goodness" or "badness".