Not necessarily.
A 0/7/34 mid laner is certainly getting involved in the team fights, and doing enough to set up the rest of the team to succeed even if it costs them their life and they never secure the kill.
A 0/7/2 top laner might have constantly dragged the enemy team away to deal with their splitpush, killing an inhibitor and letting his team get pressure elsewhere while he was pulling the enemy team after him. He could have also died while stealing Baron from the other team.
I'm not saying there aren't feeders, but saying that anyone laner who's "0/7" is automatically a feeder is a rather unintelligent thing to say.