Pulling is a safe good option imo, but there can be ways to gain more by playing in lane and using powerspikes. But if he died under enemy tower that's on him i would say.

At the same time if it's normal for your cores to die like that maybe you should be pulling less and playing behind them to protect them. Only if you are a hero that's capable of that, so you probably need a stun against storm and that still might not be enough.

So my conclusion, if that's how people play every game in your games AND you are a hero that can protect them play with them and see how it goes. But i wouldn't sacrifice my game to protect 1 guy who is about to die all the time. Up untill min 8 maybe you can babysit him, but then you just gotta let him feed. There's shit on the map to do maybe ward cliff around mid maybe gank mid you know. Can't sacrifice everything to protect one noob.