Karma falls off Late Game?

NO. was my first champ! (pre season 4) and I have loved her ever since. She deals tremendous damage the entire game, has great poking, and kiting, the whole game and is very versatile. I have played Karma in every position (except ADC) and have done average if not better on multiple occasions. In my experience even as a support (Where you lose some AP for the sightstone and frost queen's claim) she can still fire off a Soulflare (RQ) and half health almost any one but tanks AT ONE TIME. It really makes me mad when people 'claim' Karma has no damage late game because they are WRONG. She can slow down an entire team and speed up her own (Usually not at the same time but it is possible.) If any one gets close to your carry or you, you can shield who ever they are attacking and then slow them with your Q and root them with your W. The only reason I think Karma might not be the best is that her Q is her main damage dealer and if you cant hit it, you will lose. Karma's W isnt a long snare unless maxed which makes you choose long snare over big shield, because maxing her E second (you always max Q first) can give a very big shield. Im not saying there is anything bad about this it gives versatility. Do I want to lock people down or a absorb more damage. The only buff i think she could get (Without making her godmode) is to make the length of her snare always 1.5-2 seconds instead of starting at 1 and going up by .25 each rank. WHY DO PEOPLE NOT SEE KARMA AS OP AS I DO?!