Why are hi-end active monitors not more popular?

Good question.

Pros:
better driver integration with active phase control
more efficient (no power loss in a crossover)
lower IMD distortion

Cons:
less tweakable
less gear to covet
less resale market

Maybe there are some problems with electronics interfering with the speakers in the active path?

Or maybe manufactures who are good to make amplifiers aren't so good to make speakers and the contrary?

Hooking up an amp to a speaker doesn't make the speaker active. That's a fairly absurd statement.

Vibration is also not that big an issue. If it were, powered subwoofers wouldn't work. Also, the amp doesn't have to be housed in the speaker, it could be housed separately.

If you can build an excellent speaker, then you can build an excellent power amplifier. For any real audio company designing and building a high quality power amp is a trivial task. There are any number of first rate audio designers who could be hired for the design and there are literally hundreds of electronic manufacturers who can build the product.

As a group audiophiles just don't see a need for active speakers. Based upon some of the above responses I don't believe this bias is based upon any rational reason.

You forgot another really popular option (not on this forum) but Squeezebox into Meridian digital speakers. This is the simplist system.

Most people shy away from the high price of admission for active speakers. They think it is really high but when you look at the expensive speaker cable, amplifier, interconnects, stands/shelfs/isolation/powerconditioning, power cables, and even preamp. Those components will be more expensive than an active system typically, as you move toward a full range system then the two options equal out as the choices get smaller.

The Big ATC's and the active Pass Labs Speakers are pretty impressive.

My only reason: I don't like the sound of solid state amps. Otherwise ATC would be high on my list.