Everyone has their own reasons for being on SO, but the big three reasons are presumably (a) to learn something, (b) to teach something, or (c) to find out how to do something.
Answering a question directly can accomplish all three of these goals. A great way to learn something is to teach it, and if one doesn't know how to do it, they have to find out how to do it themselves first.
Answering a question with "search Google" also has its place, too. It probably indicates that the answer is easily found there. That teaches as well: it teaches people to fish rather than just handing them a fish.
SO has enough users that you'll get all sorts of questions and all sorts of responses. I'd think that really top-notch programmers will enjoy tackling the hard questions, and "advanced novice" programmers will answer the easier ones to gain traction.
And hearing, "You know, you should check Google first" is far more polite than you'd get some other places:
So I guess just deal with Google questions however you feel is best, and learn from the community here what they think of your responses. You may learn that you're too harsh. You may learn that you're too easy. Or you may learn that you're just wasting your time and should spend time doing something else.