One of my pet hates in online discussions about RPGs is the anodyne advice to "do whatever works for you and your group". Just do whatever's fun for you and your players. Stop worrying about whether one play style is better than other - lighten up! Just do whatever works! Well, duh.
It annoys me primarily because it's meaningless, of course: if anybody in the world needs to be told to "do whatever works for you and your group" they're probably not intelligent enough to operate a computer.
But it is also incredibly low-reaching and unambitious. It is most frequently used to kill any sort of debate over play styles or techniques: "Stop being mean, you horrid bully; everybody should just do whatever works for them and their group". Don't try to discuss matters, improve your GMing, or even think about games in the abstract. Just do whatever works. Keep on keeping on. It ought to go without saying that this is not a mindset that any adult human being should have.
It also simply fails on its face: how do you know what works without thinking about alternatives? Unless you are aware that there are different ways of doing things, and have analysed them in some sense, how can you possibly know what works or what doesn't?
And finally, it implies that once you have a gaming group you stay in it for your entire life - it is "your group". Again, it ought to go without saying that groups are composed of different people, and figuring out what works for one group will require a level of thought about "what works" in general. In fact, gaming with different groups will by necessity require individual GMs to come up with abstract, universal notions about things that tend to work and things that don't, irrespective of the players involved. But no: we all live in our parents' basements and game with our school friends until death.