Give a novice a 300D with kit lens (55-250 or 75-300 III) and ask him to use Auto mode/P mode (like P&S) and ask him to take a portrait at 100mm. Using a tripod and natural light coming from a window.
Give the same guy a 7D and a 100mm f2 or f2.8 with the camera on the same tripod and all he has to do is pull the trigger in auto mode.
Which one will be better?
Did he need to understand it to the maximum? All he did was pull the trigger.
Even for complete noobs, better gear will make a difference... some difference
I whole heartedly agree with this. It is (or at least can be) similar to golf. I suck at golf. I will always suck at golf. However, buying a good set of clubs helps me to suck just a little bit less at golf. Similarly, I may never be a great photographer, but decent equipment can help some of my pictures to suck a little less. I doubt anyone on here woud say a photo out of kit lens is going to match the exact same photo
taken with L glass. Without changing the composition or the lighting or anything else, it should be sharper with better color, etc., all the great things that L glass can give you.