If bot is getting 4/5 man ganked and youre not taking advantage of your laner not being there,

I more often find that the issue is people not understanding what constitutes an advantage. If I'm winning my lane (or going to be winning my lane), it's not good to destroy my opponent's tower. Assuming the enemy team doesn't scale super hard, laners who are winning should do all they can to remain in the laning phase for as long as possible. What they should do when their opponents leave is freeze the wave just outside their tower and cause the enemy laner to lose dozens of minions, which is far more impactful than a couple kills. Then, with that additional advantage, dominate the lanes even harder.

i dunno, what are you doing?

https://s1.postimg.org/441o49ymn/asdfghh3.jpg

Nothing, you're incapable of making rational decisions.

I am busy trying to set up a freeze on my side of the map.

I feel you. Whenver top teleports bot I'm going after the tower. People generally don't understand this. I'd say it has like a 60% success rate if your laner leaves. 50% if mid leaves.