It seems almost facile to point out how important video game mechanics are to a game, but they are. When doing their job, they're barely noticeable; an extension of the player and how they interact with the world. And over decades of gaming innovation, there have been countless examples of genuinely intuitive game design.
However, more often than they should, developers come up with some genuinely annoying mechanics. Fortunately, creatives are smart enough to wipe the slate clean in most cases, and are more than willing to ditch a dead idea.
Most cases, that is. Not all.
No, there are some mechanics that regardless of how annoying or genuinely frustrating they are, still cling to the industry and belabour good games. They are so fundamentally ingrained or are perceived to be popular that they are included for no other reason than tradition.
Either that, or they're considered the only way to provide a certain experience, despite being abhorred almost universally by gamers, or at least frowned upon in some respect.