Mainly because they’ve been shitty instruments for decades. The original was cool, but they were copies of Gibson EB-1 Violin Basses, though Hofner made it lighter and free of a stand in '56, whereas Gibson did that in 1958.

Objectively speaking, having played both and having owned a Hofner, the Gibson is a better instrument through and through.

https://www.violinbasses.com/history.htm

A lot of the musical equipment manufacturers are in dire shape.