Why Does All Jazz Sound The Same?

Why do dumb questions sound the same?

Squeaky squeak squeak, honk honk honk, ratta tap tap, bing bang bong, tinkle tinkle, rumble bum bum.  

God I love it!

I know you say you love it, and you are probably being a bit facetious, but for the uninitiated, it should be pointed out, that there are vast differences in many varieties of jazz. 

None of the following subgenres of jazz sound anything like each other:

Post-bop (Coltrane, Miles, Freddie, Evans, McCoy, etc)
Fusion (Return to Forever, Mahavishnu Orchestra, Allan Holdsworth, Alex Machacek, etc) 
Chamber jazz (Oregon, Terje Rypdal, Jarrett, Eberhard Weber, Jan Garbarek, etc)
Avant-garde (Cecil Taylor, Anthony Braxton, Ayler, Art Ensemble of Chicago, etc)
Jazz-metal (Panzerballett, Counter-World Experience, Spaced Out, etc)
M-Base (Steve Coleman, Andrew Milne, Greg Osby, Cassandra Wilson, etc)

Just to mention a few...

Why does all Grateful Dead sound the same?

I'm very new to jazz but I'm enjoying it, unfortunately the misses is NOT. Her opinion on jazz is and I quote "it sounds like 4 people playing 4 different songs on 4 different instruments all at the same time" 

@superblackbirddave1,
Your wife is not alone with those sentiments. Jazz and classical music will never be mainstream for the general population and I accept that. Pop,Rock, Hip hop,Rap is what millions gravitate toward and where mega amount of money is generated.

I actually feel lucky/fortunate to be one of the  "relative minority" of people who simply love and deeply appreciate the outstanding music that the jazz genre offers. Given its small niche in the music universe it’s amazing the vast amount of recordings (And quality) available.
Charles