When it comes to electric guitars if something is done backwards compared to everything else it probably comes down to some pioneer in that thing got it wrong and then everyone else copied them.

That's why the arm on many electric guitars that you can jiggle to cause pitch variation (which is called "vibrato") is often called a "tremolo" arm. Fender put a vibrato system on their 1954 Stratocaster but called it a tremolo system and that stuck in the electric guitar world.

Then in 1964 they introduced the Fender Vibrolux amp. That included a circuit to rapidly vary volume (which is called "tremolo") but they called it a "vibrato" system, thus completing Fender's complete reversal of the meaning of vibrato and tremolo.