Is it normal that the clutch on my 2004 mazda rx-8 suddenly failed?

Of course it's normal. It's a Mazda.

Google it, silly. Could be the linkage, a bracket, slave/master something or other. I dunno, I'm just a bird. Maybe there's a recall. Who knows.

When I've had the same happen is generally been due to slave cylinder failure due to other reasons.
For example I twice broke the clutch fork pivot, allowing the slave cylinder piston to travel too far & actually come out of the bore before cocking & becoming jammed.
Another time it happened I had broken the metal bracket that houses the clutch pedal in the footwell.
All of this was due to having (& abusing) a ridiculous triple-plate clutch though.
If you have a standard clutch you're either abusing it, you're extremely unlucky or there is a design flaw.

Of course in your case it could also be a number of other things. Stick your head under the car or check the clutch master cylinder reservoir & see if you've lost fluid

A clutch is a mechanical device and will wear out eventually. The clutch plate allows you to get the car moving with friction. Once the plate wears down it will become very inoperative as it will be metal to metal.

It happens to all cars.

My 1992 Toyota did much the same the year before last - master cylinder blew.

A month or so later the slave cylinder blew.

6 months later I broke some of the little springy things on the clutch plate (apparently) and I ended up with a clutch that would work "sometimes" (that was fun getting to the mechanic while it WASNT working so he could work out what the fuck was going on).

Welcome to the wonderful world of owning an older car.

Its a Mazda, force it into gear and drive it into the river.

Maybe your fat foot destroyed the world.

I looked it up a lot of people had the pedal shaft break plus many other reasons. It was just a screwed up car for clutch problems in 04-05

It's nearly 13 years old.

And it's a freaking Mazda.

RX-8s are also prone to engine failure due to carbon buildup /:

Oded here, Sounds like a simple fix. Could be a simple return spring. If it is hydraulic, then it could be a more complex fix. Just go to Mazda and ask them. Then go to a trusted mechanic, or just go to a mechanic directly. Money may be an issue however getting a quote is free, or should be.

Oded....out