I really, really don't want to start a big thing with this, but since you are semi-new:
1. When someone resigns it does not change the points you receive. A resignation is treated as a loss just like a checkmate. The ratings don't differentiate.
2. Resignation in a hopeless position is a sign of respect. Your opponent is admitting they are lost and agreeing you have the ability to checkmate them and avoid a stalemate.
3. As many here will point out, everyone has the option to play however they want with their time and nobody has to resign if they don't want to, but resigning in lost positions is considered good etiquette by most players.
WHY do people quit when thet are about to lose!?!?! If you just played for 10 minutes and you are left with your king and 1 pawn, don't quit! It's too late!!! Just b/c we both know you have lost, it doesn't mean you can just go and quit! Now your rating doesn't reflect you losing and mine doesn't show me winning!!! It's not fair for people to quit when they have clearly been defeated. Why run!?! I don't believe a lot of scores are accurate b/c of people abusing the resign button. It's just not right.