When you say l2p you're probably just suggesting that they need more practice. Noob basically means the same thing. But that's not the way these words are received.

Whether we like it or not, the internet breeds its own vocabulary, community, and sense of ethics. And words/phrases like l2p and noob are taken as insults. Why? Because they're used as insults. Look all over the web, I guarantee you that these words are not being used as a contraction for a helpful phrase on message boards or in other games.
I'm pretty sure that f*** started out as just a word too.

Also consider this. When online we have a tendency to overreact to things because we, as people, have lost our ability to feel empathy. This is caused by our inability to see the other person's facial expressions. (Yes there are studies on this, no I won't go find them for you I'm tired.)

Further, consider the kinds of people you want to play this game with. Do you want to play with level-headed people, or the hot-tempered.

So instead of just blurting out a phrase that you KNOW has become an insult. (Don't pretend you don't know.) Try being the calm one, express a full thought. If they turn into the hot-tempered one after that then don't intentionally egg them on, don't pursue their anger with your own. Remain calm, be witty, or just /ignore. And if you honestly didn't know it was insulting then just apologize and move on.

SHORT VERSION
1. Face the facts. Certain words have become insults due to their use.
2. People online have a tendency to overreact, recognize this and watch yourself.
3. Try to remain the level-headed one in arguments.
4. Don't pursue their anger with your own, /ignore if necessary. At least, it takes a lot less time.

Keen piece of insight.

For me I'm not punishing someone for saying l2p or noob a few times in a game. I am punishing the people who seem to be throwing out snide remarks after every single mistake or single out another player and just harass them all game about how poorly their doing.

It's OK to voice your frustration. It's not OK to try and ruin the game for someone else because you're frustrated.

Well, l2p is telling someone they don't know how to play LoL.

Calling someone a "noob" is the gamers equivalent of calling a black guy the "N" word.

Its the way that you say it. When you say "L2P NOOB" its not gona be in constructive criticism. If you want to help some1 you should say things like "try not to over-extend, wards are your friend" or any other dumb catchy phrase that can help. You have to give the new/bad players advice on how to improve instead of just reinforcing the fact that they arent as good as you

You would called a black person a Noob too?

jokes aside

I agree fully with the OP, l2p and Noob are not helpful in anyway, they are directed as insults and serve no practical implications whatsoever.

A i said in another thread, i feel these things don't necesarilly come under 'offensive' but more 'Negative Attitude' Yes they are offensive but i don't think they are on the same level as a racial slur

I judge each case individual, i don't immediately pardon someone if they're been reported for calling people noobs, but I also don't imediately punish them

MY PEOPLE!

*tears of joy*

Where have you been all my life?

Well, I did say gamers equivalent. And both terms generate feelings of inferiority.

I totally agree. When you see someone struggling then just pointing out that they're bad isn't helping anyone.