I understand what you're saying and you're allowed to feel that way. Don't let some random dude like me online come in the way of that. Holdo's whole lightspeed thing really came out of nowhere but I mean there's a few explanations for why it wasn't used in the Clone Wars.

Firstly, the ship Holdo was operating wasn't designed to be used as essentially a kamikaze rocket. Hyperdrive isn't meant to be used as a weapon, which is why it wouldn't have any outside controller from outside of the ship for the same reason you can't operate your cars steering wheel or breaks from outside your car. That's just a plane safety hazard. Hyperspace was only designed as a method of transport and it's pretty clear that going Lightspeed to take out the Dreadnought was a very last minute plan when their other options were running dry.

Secondly, it wasn't used in the clone wars because