Most of the 'east coast sound' speakers were designed by, or came from companies affiliated with, Henry Kloss. Kloss died ~20 years ago and the whole 'east/west coast sound' thing generally died in the 1980s. There has been
a recent 'reboot' of KLH speakers, but Klassik knows not how they sound.
Klassik knows not how popular American speakers are in the UK. Based on what Klassik sees here, it seems most here are not using American speakers outside of Klipsch and maybe the odd reference to Magnepan speakers every now and then. Both of those have rather unique qualities even compared to other American speakers so one should not assume too much from those. Comparatively, if one goes to a US Hi-Fi forum, one will see many people using KEF, Monitor Audio, B&W, Wharfedale, and so forth speakers. For whatever reason, bread & butter US speaker companies such as JBL/Revel, SVS, Polk, Ascend Acoustics, and so forth are not even on the radar here it seems. Perhaps ASR is behind the Harman aversion here.
Some of the popular US speaker brands here now, like Ascend Acoustics, use a direct-to-consumer model and so perhaps this explains the lack of popularity globally since they don't have much of a dealer network.
Anyway, it seems to ole' Klassik that US Hi-Fi enthusiasts give more consideration to suitability for A/V applications rather than just for 2-channel music. People here might look down on such things, but keep in mind many of the Americans wanting speakers for A/V purposes are the ones buying KEF, B&W, and so forth.