Junglers ignoring team to powerfarm.

Aight so before I start, I'm just gonna say that I'm pretty low elo- mid silver is my guess once I finish placements.

I've been thru several games recently where my jg will deadass only powerfarm and won't be bothered to gank an incredibly overextended lane or help with any skirmishes that break out. Obviously, there are many factors that go into a jglr deciding to gank (health of enemies, matchups, lv advantage, lane placement etc). but what's the deal with this powerfarming that's going on?

Your job as a jglr (and everyone else) is to help your team win, not to just fucking clear every single last camp in the game. Sure you'll earn gold, but farming is a means to an end, not the end. Is this just something that happens at low elo? Do jglrs just get dead-set into the mind set of "of shit, I need to be farming my jg so the other jglr doesn't sleal it!!"? Or is is something else that I'm missing.

It's just so tilting to play 4v5 for the first 20 minutes, and by the time that our jg come back with thier items, we're down too hard and it incredibly hard to come back, even with a fed jg.