OP I feel for you. I agree with you. Decay and real time mission timers are not fun. Nor do they add challenging. There is nothing harder about playing for longer stretches. These mechanics add nothing.
But they take away a lot. Like, say, potential customers. The grown up sort, with their own money.
But good luck. These self appointed "hardcore gamers" have made a willingness to be crapped on by shoddy mechanics and tolerate nonsensical levels of grind part of their identity. They take well to the truth of how ridiculous a lot of this stuff is.
Hardcore? I get a few hours a week to play, maybe, and right now I'm a few thousand light years out in the Black and heading across the core to the far Rim, I'll be out for months and months. My rep with the Federation, Alliance and Empire, already as low as they are going to go, because I haven't done a single mission in weeks, and I won't do another mission for many months. Oh, noes!!!11!!1!! I'm now Friendly 75% with all 3 major factions!
Those saying, 'don't let the missions matter to the BGS if over X time', uh, you DO realize that all missions are a product OF the BGS at the time it's created, right? There's a reason you see the missions you see when you see them, it's not just to annoy you by not giving you all the Kill Pirate missions you want or all the Charity missions you want, so yeah, that's rather the point of those missions being time sensitive, it's a living galaxy and you are directly interfacing with it when you are online, everything you do in the bubble has repercussions, regardless of whether you know it, realize it or give a damn.
STO, pause, yeah, on specific missions you do get that, but that's because it's not a real time game really now is it? And your actions have 0 influence on anything in the game world as well, so...really, how about you pick a game that has your actions and inactions influencing the game world and see how many of THOSE let you pause the game. All 0 of them.
Again, this is NOT an offline game, you are interfacing with a nonstop always running game world where the things the players due have a direct influence on how the game runs, so missions have timers, you not being around costs you reputation, makes you fail missions, all that stuff, and it's not at all unusual, special or unique, MANY other MMO games do this exact same thing, including timed missions. You don't like it, get a refund, go find an offline game where nothing happens except when you have the game running. This isn't new, this isn't unique to Elite: Dangerous, it's been a FEATURE of MMOS for a long time, and before that it was a FEATURE of MUDs and other games played on BBS before the internet was a thing.