Well, everyone has different reasons.
Mine are several-fold:
--Since Klipsch is a company, and has to make money, they cannot afford to use the 'best' (subjective of course) of everything, and be able to make a profit, since then almost no one could afford their products.
--I bought a 'real' Khorn, to take it apart and assess, comparing it to the ones my father taught me how to build, from original plans that were reverse-engineered and drawn up at Bell Labs in 1945 (I still have the original plans!).
I now have 7 of them I built. (would make a killer 7.1 system

)
Since:
1). I don't need to make a profit
2). Don't care what they cost
3). Don't care about how long they take to build
4). Can pick-and-choose the best materials, drivers and horns (here is a hint: the bass unit materials are denser than water).
5). Use modern-technology crossovers (no passive stuff here)
6). Want much high power-handling capacity
7). Have access to an anechoic chamber, spectrum analyzers etc.
My belief is to take a really good thing, and make it better. (JMHO)
Simple enough.