Like any game, they will only improve things to a point. There game is built basically around RNG giving guardians the chance to get better gear. Yes players say the rewards do suck, and I agree there is a large amount that do suck. Bungie based the loot table around rewards that they thought were useful. Strange coins is in the loot table since you can take them and purchase some strange coins for drop chances, buy exotics you don't already have (or ones with better stats), change your exotic armor stats, or buy some heavy ammo. You have options of how to spend them. Yes there will be a point when they start to get useless in terms that you have exotics (all or ones you want), and got good stats. You can use the coins to buy some exotics engrams that could drop at 310 if your light 310+. Use the 310 gear or infuse it to boost more. The weapons or armor give some players options to boost characters. You can either use the gear to infuse others, get legendary marks, or boost since you like the gear. The nightfall is useful to players but there is a point it is no longer useful. You stated you been playing since launch, so I am assuming you already gotten almost all the exotics. You also may have good gear that makes you a high light level (over 300). You may be at a point where you no longer need to infuse gear since you gear over 300 and need raid gear to infuse. Others may not, and do the nightfalls to boost. Players get to a gray zone where activities seem really useless since they don't get anything good and can't move up or there is nothing left to collect (exotics). Its a zone where players get stuck and can't gain light levels so they get mad. This happens in all games where players got to grind. Imagine how angry you will be when light 219 and you have a 319 piece of gear. You will hate the activities since you won't be able to reach 320 for a long time. Bungie takes the gray zone into consideration since its a grinding game and there will be a point that players reach where activities seem to have no point in playing. I had all the year 1 exotics by 3 weeks after Crota's end came out and again after about a month when the second dlc came out. At max level and with all the exotics it seemed useless to play, even before than.