You mean like the instant teleportation we've had since the game came out when we die? Not just the commander: but an entirely new and completely identical ship.
Or the instant teleportation that fills and empties our holds (I notice that takes zero time)?
Or like the instant repairs that happen when my ship is broken and I pay the station?
This isn't new. Pretending it is is just whining. Either the feature improves or degrades gameplay. That's it.
Being dead is not playing - the rebuy screen is the portal back into the game. Of course, some players will use it as a method to return to a distant location - at the expense of a rebuy in the ship they left there in.
Loading / discharging cargo does not change the location of the player in the galaxy - and I agree that it takes too little time - however it is probably short because players would get very tired, very quickly of waiting for cargo movement as it would be something they did in most, if not all, docks. Same for repairs. Same for changing modules / weapons / utility mounts / decals / paint. In effect the lack of delay for these activities (other than menu navigation) constitutes a series of concessions to convenience that have been in the game from the outset.
Visiting the rebuy screen is not something that can reasonably be described as playing the game nor it is visited so regularly, I expect, as to become part of a player's normal game-time....
Permitting players to jump hundreds / thousands of LY instantly to the location of a ship they have chosen to crew for and then disembark in the location of that ship would not be consistent with the game rules - there is no gameplay related CMDR teleportation in the game (yet).