Why can't you just end?

I win mid, I roam and win your lane because I see your lategame carry potential and I know that's where I fall off. I literally give you the power in your hands and you are at the nexus when everyones spamming "END END END" and you say..... "Nah!" back and spend your 3200 gold because that power got to your head but you dont realize they just got stronger dying/buying and we got weaker because me being the only other one fed I am falling off more and more and barely able to get my damage off (Talon)

Why do you people do this? >_<