I'm not sure he's entirely wrong.

I have a theory that a large fraction of the population is not conscious. They go about their lives, they still work and think and have emotions in some form, but they don't actually experience. In other words, they're P-zombies. (Note: I do NOT support any actual action based on this idea. This certainly doesn't suggest that it would be morally acceptable to do anything to that group that wouldn't be acceptable to do to the rest.)

This is by analogy to mental imagery. For a long time, there was a debate over whether people actually saw mental imagery in some real sense, or whether it was just a way of describing more symbolic thought. These days the general consensus seems to be that it varies, where someone might see extremely lifelike images, or more vague images, or none at all.

Since it's all about internal experience, people had a hard time understanding that their experience wasn't necessarily the same as everyone else's. The same might be true of consciousness.

This started out as mostly a joke or a thought experiment, but more and more I'm thinking it might actually be true. Statements like Andreessen's really push me in that direction. It's such a baffling statement... unless Andreessen is a P-zombie, then it makes perfect sense. And if he is, he probably thinks this whole consciousness idea is just a weird analogy for perception, and thinks we're a bunch of weirdos for acting like his statement isn't something obvious.