There are fundamental elements of game design that are objectively good. Not to say there aren't game design ideas that overlap or conflict with one another, but you can point to things as an example of a game system, level design, gameplay mechanic and the like as objectively good. As such, a game that drastically goes against these things is likely to be objectively bad, even something like Deadly Premonition is an objectively badly designed game, but it's a rare case where it's actually pretty great for the charm and goofiness that it intentialy revels in, but nonetheless it is an objectively badly designed game.
It's like writing. There can be poor sentence structure, grammar, pacing and dialogue and a story can be objectively bad. However, it's it's written on purpose that way for the meta narrative (depending on the narrator's intelligence, mannerisms, etc. then the material can be elevated. But at its core, a story can be objectively poorly written.
Now, a lot of times people conflate objectively bad with a game they dislike, or a game in which it has both good and bad design choices and for that individual the bad outweighs the good. Final Fantasy VIII is a good game, but some of the things that bother me prevent me from seeing it as an exceptional game the way some others do - I can point to some design/writing choices and say they are objectively poorly done, but I cannot say the entirety of the experience is objectively bad nor do I subjectively think it is bad.
