bc rich are rubbish guitar how they get sold is beyond me
The original BC Rich guitars were actually very good hand-made instruments. Geared totally towards the heavy player, but still good. As with many other small companies though, they went mass-produced, the quality dropped, but they continued trading on the name. Dean are mostly the same (although they still have a small "custom-shop" building the better guitars like the Soltero). Parker have also gone South since they were bought out by Washburn.
Yet there is a distinctive "Ovation sound" - or there was in the 70s. And some artists wanted that sound.
Yup. The percussiveness does help them cut through and that became popular for a while. Like the Steinberger electrics did with their very even, but ultimately rather bland sound. I know Joan still uses one on stage (alongside a Les Paul and an Anderson electric), but she's one of a very few. For most people, once the novelty wore off, they moved back to their old Martins, Taylors or up to their boutique acoustics.