Quantum computers require both very specific configuration for each problem, and cryogenic cooling. Both of those issues mean there's no reason to suspect they will find more than use as a daughtercard any time soon. Memristors, on the other hand, could replace CPUs, RAM, SSDs, bulk storage, FPGAs with one consistent lattice, a totally unified memory architecture, and an economy of scale that I don't believe has ever existed before.

And that's BEFORE you do any of the exotic research of moving the computing elements around during operation. Just imagine if there was no memory hierarchy, where accessing a byte in mass storage is as fast and as easy as accessing a register. Quantum computers can't replace commodity hardware and there's no reason to think they will. Memristors, on the other hand, are one of the fundamental circuit elements and are destined to become as widespread as resistors, capacitors, and transistors.

The speed of light dictates that there will always be a memory hierachy. A nanosecond is just a couple of inches of wire [1]. Communication overhead and heat issues are what ultimately limits computational power [2].

[1] http://www.youtube.com/watch?v=JEpsKnWZrJ8

[2] https://en.wikipedia.org/wiki/Limits_of_computation

If you open the box their wave state collapses and they are either excited or bored. :-)

(ok that was a long way to make a Schrödinger joke) There are a lot of people who are very excited about Quantum computers and working on them, as they get more 'real' people on the fence move over, etc. I watched this on a smaller scale with 3D printers, as only a few people were excited about them and then as they demonstrated more and more interesting things the wave of excited people expanded outward from that core.

And of course, people do get excited about quantum computers...millions and millions of $ a year excited.

But yeah, their mostly non-existance is exactly why people aren't more existed.