The subjunctive prelude "One might speculate..." signposts the structure at the dozen paragraph scale. The author is both wondering why people play Farmville an

The subjunctive prelude "One might speculate..." signposts the structure at the dozen paragraph scale. The author is both wondering why people play Farmville and providing a description for those unfamiliar with it. He works through a list of hypotheses, stating them and describing the features of Farmville that leads him to reject them. The proposed alternative sentence is neither informative nor structural. "People may play Farmville because ..." is uninformative; we were hoping to be informed that "People do play Farmville because ..." or that "People do not play Farmville because ...". Nor does the sentence help the text flow. It is like encountering an if statement while reading code. Now there are two paths to follow, may and may not. The sentence imposes a cognitive load on the reader, but for no reason. The author is about to explain why not.