Horn based loudspeakers why the controversy?

I listened to horn speakers for the first time recently, Trenner & Friedl RAs powered by Shindo. It's either my first or second favorite setup I've ever heard, and I've heard all the big brands. 

Over seven decades, I've owned both horn and direct radiating speakers.  The way each presents its sound is akin to what I experienced in Vienna several years ago. I was fortunate to hear the VPO play in both the Staatsoper and the Musikverein.  Same orchestra - - but playing in two clearly differing sonic venues.  
IMO, the playing in the Staatsoper was akin to direct radiation/cone speakers, while the playing in the Musikverein was more "in your face" like I had experienced with my horns. 
I enjoyed them both, although  each presented the music as different audible (and emotional) experiences. I guess it's a choice as to which approach you prefer as a constant diet over the weeks, months and years. 

I have a pair of Bob Crites Cornscala’s with DeanG crossovers and they are amazing. They do a lot of things really well with exceptional detail and midrange. Very revealing speakers. YMMV

K horns are availble used  $2500 up. Altec a7 $800 and up EV has full horn options under a $1000. Most of these are a good step up from LaScala. The low used price allows room for well thought out upgrades. If ones in the know world class horns can be built under $3k. Or go on craigs they exist all over the USA.