Yeah this has been discussed a lot. No reason not to keep bringing it up, though, because it certainly is a problem with the game.
Ideally mission timers would be used for challenge purposes only, and would only count down when you are actually in the game. If this were the case the timers could be much shorter and could be balanced around the tasks to which they are connected.
It’s profoundly idiotic to have the timers counting down while you are logged out of the game, because there’s basically NO way to balance something like that.
Mostly what Frontier uses the mission timers for is to make sure whatever mission you’re running isn’t too far out of sync with whatever BackGround Simulation system state generated the mission in the first place. They ALSO sometimes try to use it as some sort of challenge incentive, but these two approaches are fundamentally at odds with one another.
People run missions for the personal rewards as well as to manipulate the faction and system states of the BGS, and the timers are less of a gameplay design element and more of a safeguard to protect the BGS part of the game from manipulation.
A good solution - apart from, you know, the work involved in making it - would be two different mission timers: a shorter one which ticks down only while you’re signed into the game, which results in failure when time runs out (plus maybe a bonus payout for completion under “par time”), and a longer real-time one like what we have now, but instead of wiping your mission at the end of the countdown it would just forfeit all BGS and faction influence effects.
That way pass/fail/bonus timers could be used by the devs in mission design as an element to reward efficiency and skillful play, rather than just as an automated “cleanup” tool for maintaining the BGS.