Combat isn't based on SC, nor vise versa.Supercruise will never be changed because half the game mechanics... combat/interdiction, exploration, scanning and more are built off this aspect of the game. It's a space game space is big you're gonna need to travel. Engineers, Guardians and Fleet Carriers already halfed the travel time. It's not even that bad. Sorry OP I can't really agree with you one bit.
Exploration - swish and miss again. Why couldn't I use the DSS from normal speed? I see really ZERO reason having to be in SC for that. Z - E - R - O!
Scanning - He swings... and misses again! We already do all that remote via telescope. Thanks for playing though.
Probing - you didn't mention it but I'll give you partial credit for it.
Interdictiion - a real PITA part of the game, it would make more sense to remove the no fire zone and have people slug it out in or around the station.
Guardians didn't halve the travel time. They shortened it a bit with boosters, didn't alter the SC part though./
Engineers cut down on the amount of jump-honk-scoop bits.
Fleet carriers can eliminate some of the excruciating SC part of the game. But if they can jump to a planet, why can't we? I'd be happy to install a module on my ship that allows me to skip a 5mins or more SC travel time. I'll even carry tritium with me!