The 5-string bass was not, as some think, developed from the use of synth-bass in foppish New Romantic 80s bands. Quite the opposite; it came from the dark obsession with mind-alteration in Thrash Metal. Whereas the guitarists spent heavily on amphetamines, which made the riffs sound quite melodic to the player at least, the bassists found that just playing the thick string no further than the 3rd fret - while pushing the body of the instrument into their groin - allowed them to drool in a world of their own (usually at far left of the stage behind the PA cab).
Like any substance abuse, tolerance set in and Hipshot extended the depravity by releasing the D'Tuner. The scrotal flobbling caused by the reduction from 41Hz to 37Hz allowed them to corner the market. That was until some unscrupulous lab geeks came up with the idea of a 5th, even thicker string that wasn't limited to D but could go right down to 31Hz. Cleverly, they marketed the invention as "B C Rich" to promote the two extra-low notes.
Hipshot sent out their bulls to take down the geeky rivals invading their patch but the shadowy nerds simply created the plausible sounding character "Bernardo Chavez Rico" as their Boss Man that Hipshot, of course, never found. Still, the turf wars - and the gonadal injuries suffered by stupefied Thrash bassists - alarmed the Senate, who passed the Needlessly Pointy Bass Bodies Act, which (like Bitrex in meths) discouraged pressing the BC Rich into the groin. Soon, the 5th string fell into disuse and became a handy thumbrest.