Not that they'd imply (infer?) a plot when there wasn't one, more that, prior to loading a game up, the box art and inlay descriptions would often have them imagining a wonderful gaming experience that, upon loading, the software spectacularly failed to live up to.
A particular example that's stuck with me is the computer game adaptation of the Fighting Fantasy book, The Warlock of Firetop Mountain. I was a massive fan of the Fighting Fantasy series (pretty sure I bought every single one, up to a point). They were effectively the analogue, more portable equivalent of a text adventure, or a cut-down, solo D&D campaign... yet the game adaptation was a horrific maze game with stickman sprites, effectively a clone of Halls of the Things (although 'sequel to' is probably more accurate, since it's by the same developer). Sure, on a basic level, it was an adaptation of the original book... but it didn't even follow its geography, and most of the mechanics were removed in favour of 4-directional movement within the maze, and 'waggle your sword to attack'.
Never been 'in the industry', but spent a lot of time in arcades back in the day, and have played some 80s games from Japan via emulators... My impression is that they tended to apply a story (random though it may be) to even the simplest of games... But then, I tend to get the impression that Japanese kids were/are more inclined to read than their Western contemporaries.