The JBL line is different. The woofers are descendants of the original D130 woofer used in the early JBL HiFi speakers in the 1950s. This speaker, and its many variations, also became the dominant speakers in electric guitar amps in the 60s that created the rock guitar sound. This led JBL to use similar drivers in their early studio monitors like the 4310 and 4311 that were designed for the higher SPL demanded by rock artists and producers. So those monitors and the consumer versions that followed all use woofers that reproduce electric guitars particularly well.
That being said, JBL speakers are also great for classical, jazz, and any other form of music, as in your original premise. Audiophiles tend to avoid them because of their association with rock, to their detriment. I've seen all the "Junk But Loud" jokes but I smile because it keeps the price down on resales.