How hard is it to hit the nexus?

Is there anything more frustrating than playing with people that don't know how to close a game? Why does it seem to be so hard to understand to hit the nexus and win? Run up and hit the nexus to end the game. I mean... I didn't come to just rant but... what about this concept is seemingly so hard to understand? Even when you ping, or outright say "Everyone is dead, end the game" when there's absolutely nothing to stop you.

• Your team gets a clean/semi clean ace with 50+ enemy timers OH but i have to complete that 6th item just cuz so im gonna B and give the enemy a chance to recover.

• The only thing stopping you from running up and hitting an exposed nexus is a support and a half health jungler OH but lets waste time farming jungle camps or split pushing to a tier 2 we didnt get

• We got another team ace and their t3 towers are down, all our damage is alive but WAIT we NEED to kill baron first at least once this game to give the enemy a chance to respawn

And then your lead is lost because the enemy team had so much time to recover, hold, and hit their late game spikes they can turn the game around. Your team could have won 10-15 minutes ago but time is insisted on being wasted with things you don't need to do at the time you can just run up, hit some stones and end the game. Is that really so hard?