You are not the smartest person, there is always someone smarter then you. Some smart people are just starting out and they don't know the processes that you are so used to over years of doing it.
So, when they come here and ask something (usually with specific method in mind explained) you, as an experienced marketer, will recognize the potential much faster then "the noob" will ever get a chance to squeeze it out of its juice and full potential. I think this is why its good to help out people starting out, apart from moral satisfaction and the fact, that someone helped you when you were starting out so you want to accumulate some karma points.
Competition is never a bad thing. You just need to evolve and not be lazy, think of new stuff, innovate.
That's basically what black hatters are doing with new methods and new approaches. Trying to get them saturated and help people get into it, thus making them money, so google or any other search engine get swamped and not able to keep up with new shitstorm.