Time-gating is fine, but once a quest is unlocked it should stay unlocked and you should be able to do it at any time. Personally, I work, have a family and can only play at certain times. I can not drop what I am doing to play a mission just because it randomly decided to activate and is gone. That is as bad as RNG. There is a good change that I could miss a quest line every time it opens up if it is not the weekend. I do not mind the slow leak of new content just dont take it away and if you are going to take it away let us know exactly when it will be back. I know Xur is only here from Friday - Saturday. I can work around that because it is consistent. I know that Trials is only the weekend. Iron banner is announced in advance so you know when it is coming.