It's the difference between 'potatoes' and 'mashed potatoes' ;)
(edit: I should clarify "same technology" to mean "same use of address space separation". Microkernels don't need to use virtualization technology like VT-d instructions because their separated modules don't need to think they're running on unadulterated hardware.)
Complexity is the difference.
Hypervisors "won" because it was easier to implement; They only had to add another layer to the stack, rather than fundamentally change the structure of the OS.
The outcome is a more baroque collection of code, though. Worse truly is better.
And the fault tolerance argument applies both ways. That's generally the reason behind VM sharing too. One simply separates processes along lines visible to the application (i.e. memcached vs. nginx) or to the hardware (FS process vs. display process).
Potato, potato. This simply isn't something worth arguing over. And it's silly anyway, because there are no microkernels in common use that meet that kind of definition anyway. Find my a consumer device anywhere with a separate "display server", or one in which the filesystem is separated from the block device drivers. They don't exist.
(edit rather than continue the thread: X stopped being a userspace display server when DRM got merged years ago. The kernel is intimately involved in video hardware management on modern systems. I can't speak to RIM products though.)
Blackberry, every computer running 'X'.