I agree with some of the other people on this site. The main reason that I started answering questions was to get my hub score to increase. Higher score means more views to my hubs, which in turn give people more exposure to what I have to say.
Always remember, there are no stupid questions...just stupid people asking questions!
All kidding aside, most questions on hub pages serve more as a thinking exercise or debate. They open the doors to discussions that enlighten others and help to form community bonds . Of course there are always the questions that are easily answered with a few words, but I normally shy away from those.
Finally, there are the questions where people seem to need guidance, For example, the last question that I answered had to do with driving traffic to your hubs in order to make money. This is a concern among most people on hub pages due to the fact that the reason they signed up and posted was to earn an income.
So, all in all, most of the question posted on hub pages are worth taking the time to answer. I don't know about everyone else, but I value the opinion of those who take time out of their dailt routing to help out those who really need it.