Just FYI, "Playing Safe and farming" does not mean you're going even in lane.

I say this specifically about mid lane. Why? Who wins lane is determined by more than just statistics. Mid lane has always been regarded as one of the most impactful roles in the game. This is due to the laner's ability to roam early game and still get enough gold to scale well throughout the mid to late game.

I have always believed that one of the most important parts of carrying a game is to be pressuring the enemy in the early game. Having pressure will cause the other lanes to play more passively. It will give your jungler more control. This is what can really help push an advantage early game.

Now, let's get back to mid. Let's say you're Zed and you're winning by just a bit in CS. The enemy mid laner, someone like Syndra/Lux/Xerath, is playing passive and mostly just farming and letting you push in. So, naturally, you roam bot, and whether or not you get a kill, you're likely to give your bot lane the upper hand in the 2v2. You could invade with your jungler and force their jungler out, causing him to lose farm and XP. Essentially, having the pressure advantage in the mid lane allows you to help your teammates at a minimal cost.

Now, at 20 minutes, even if you are even in farm, even if you aren't that fed from getting kills in other lanes, your team is much more likely to be ahead because of the pressure advantage you've exerted.

So, it's not really reasonable to blame your team if you're mid and got pushed in repeatedly while the enemy mid laner was putting pressure on the rest of your team. It's not always your fault; some matchups just work that way, such as many immobile mages into Zed. But the mid lane matchup goes farther beyond just stats. So playing safe is only advisable when you'd be at risk of being killed otherwise or you scale significantly harder into the late game, which really doesn't happen in that many cases.