My thought are similar to Bianca's. If someone is honestly trying to do Mathematics using Mathematica, I enjoy helping, even if their problem is more mathematics than Mathematica. I prefer to point them in the right direction, sometimes by showing a simpler example of Mathematica functionality which I think would be useful in solving their problem, rather than actually solving it for them. My assumption is that they want to learn by doing, and I am more likely to respond to someone who is clearly trying to do their own work.
But for some, that assumption is clearly inappropriate. For someone who just posts a problem saying, "Please help! I need the answer", I am not so interested in responding because I think that just providing an answer is not really helping.
To some extent, I think this is a problem Wolfram is encouraging. They are clearly pushing into mathematics education as far as possible, now even emphasizing free-form input, encouraging beginners to just expect answers without truly understanding the mathematics. This may be fine for visualization, but I have deep reservations concerning the true usefulness of computer assistance for learning mathematics, at least before reaching applications of differential equations where posing the problem is the real issue and numerical methods are required for solution.