Why are tweeters so high off of the ground in many tower speakers...

random tail chasing, marketing and a lack of real engineering skill combined with a lack of enduring principles ?
i always get a crackup out of an 8' tall Diana Krall singing a stinging Case of You like she is standing on 6 cases of vino....

i will say measuring listening position ear height and a few other very important variables is key to a properly setup pair of Vandersteens and yes tilt is important.

Thanks to all for their input.  My question was more general than one that concerns my set-up.

I referenced my speakers as a starting-point for the discussion rather than a plea for help.  But, since many respondents have taken the time to address these speakers let me say thanks and fill in some details.  The speakers and I sit in an equilateral triangle nine feet on each side, and they point directly at my ears.  My room prevents me from going back another foot or two, which I think would be beneficial.  I am very happy with the performance of these speakers in my rig, very rarely do I hear anything better.  I use four monoblock amps: Jolida 211 Fusion tube amps on top, and Wyred For Sound mAmps on the for the bass boxes; crossover is at 70 hz.  

I asked the question because I see so many tower speakers where the tweeter is at the top, not close to average ear level.  Perhaps this is because of the "loudness wars" and crazy emphasis of top and bottom in a lot of pop music today.  My own listening doesn't include this type of music and so I wonder how these speakers would do on classical and jazz and acoustical music in general?  I think that they would need a listening distance of twelve feet or more before the tweeter would cohere to the sound.  Any Revel Salon owners out there care to comment.

A competently designed speaker will use the vertical dispersion characteristics of the tweeter (and upper midrange) drivers to great advantage to provide realistic and natural perceived height of performers and instruments in the soundstage as well as critical tonal impact at an ear height that should be specified and adhered to.

I built a podium for my listening sofa to sit upon to achieve this as it was too low without and I suspect this is an issue in many such situations.

Dave

....................... I can say the Artemis EOS were one of my favorite speakers I've ever owned.

I never owned them but I loved them.

Keeping the tweeter away from the floor delays the "floor bounce" effect, improving perceived clarity.

Designers will strive for wide horizontal but limited vertical dispersion. Normal dome tweeters have a conical dispersion field however. They disperse vertically and horizontally equally, which presents a little bit of a challenge.

Revel (and others) will use a waveguide to help shape this dispersion to more of an ideal pattern. The floor and ceiling do not need to hear the speaker after all. :)

Best,

E