This is a sentiment I’ve heard repeatedly over the past week or so, most recently in a quote from Justin Rhoades:

It’s like a pendulum swinging from obvious visual affordances to engaging kinetic ones. The parallax effect, the physics of the messages bubbles and I’m sure many other ‘kinetic’ behaviors are new to devs in iOS7. Apple wants apps to use more motion and less visual design.

Let’s talk about what an affordance actually is. Here are some examples:

The moment you see this object, you have a sense not just of how to use it, but of what it would feel like. You can feel your palm on the lever, your knuckles firm on the grip, separated slightly by those bumps. You’re anticipating having to choke down somewhat for leverage, clued in by the ridges toward the end of the handle. You may already be planning to pop off the cap by thumbing its little tab, and you’re aware you may need to work the plastic retainer a bit to counter its natural bend and keep it from springing back into the line of fire — or, as a last resort, perhaps sacrifice some grip strength by looping your index finger around it. You might not be certain what the metal knob is for, but you know from the knurled edge that you can turn it and that there will be some resistance. Shape, material, and texture combine with your experience to yield intuition, which lets you capture all of these details instantly given nothing but a glance at a photograph.

That’s what affordances do. They operate on the boundary between sight and touch. You see a thing, often from a distance, and its affordances give you enough information to simulate, in your mind, the sensation of manipulating it. Unconsciously, you configure your fine motor system in advance, so that by the time you get to the door handle, your hand is already forming the right shape to grasp it and pull the door open.

When affordances are misused, it’s more than a little frustrating:

And when they’re entirely absent, it can even be dangerous:

(Trapped in a burning building? Hope you can read English.)

iOS 7 may be “trading” affordances for kinetics, but only in the sense that it’s losing the former and arbitrarily gaining the latter. They are not interchangeable. Kinetics, or UI Dynamics in Apple’s parlance, are visual effects that occur while you interact with an object, or afterward. (You pull up on the camera icon and let go, and the lock screen falls back down with a realistic bounce; you scroll quickly in Messages and the word bubbles act like they’re mounted on springs.) But affordances can only help if they appear before you interact. You need to see the handle to mentally feel how to open the door, or even to know that it’s a door in the first place, regardless of how smoothly it’s going to swing open. In user interfaces we call this trait “discoverability.” (“Intuitiveness” is another good word for it. So is “joy.”) In the real world we don’t call it anything because it’s a basic operating principle that keeps us from walking into walls.

Affordances are the baby to skeuomorphism’s bathwater. When they engage our instincts just right, they create an emotional bond, and the unfamiliar becomes inviting. Without them, it’s just pictures under glass. It makes no difference how flat, how deep, how minimal, or how ornate the look-and-feel is if it can’t show us, when we look, how to feel.