Evidence in the series itself supports Q not helping....When did he ever pop up in the last act of an episode to save the day?
And my own perception of time has changed considerably as I've grown older....I can only imagine what it would be like for a being as long-lived as Q.
Q is looking at a much bigger picture than we or the show's heroes are. His relationship with Picard/humanity has never been as simple as "I like these people, I'll help them out." When he "helps", he helps in his own way, on his own terms, for his own purposes.