There's much more to choice of belief system than "because people need to think more." By illustration, I offer a rather long and drawn out tale that I will attempt to condense by means of reference to one of my favorite books, "The Illuminatus! Trilogy" by Robert Anton Wilson. One of the characters in the book is suddenly enlightened, a kind of light switch in his head is toggled, whereby he suddenly saw things for what they were. This was called "seeing the fnords." And to his shock and amazement, there were fnords everywhere he looked that he just hadn't seen before.
I postulate that the question, "Why are you a Wiccan" is generally asked by those who cannot see the fnords. "Narrow minded" is an unfair characterization, in that being narrow minded is in itself a conscious choice when presented with contrary information. Failure to contemplate other possibilities is a much more passive process, especially when the information that would cause the process of careful contemplation to begin is often simply not available in a form that would trigger the appropriate response. In other words, their reality is a subset of the whole. This reality has labeled as "truth" the religion that they were brought up with, exposed to, and validated externally (usually through others, or through the plethora of physical monuments such as churches existing as far as the eye can see). Oftentimes, alternatives are not presented in a form that trigger a thoughtful response, and instead are passed off as whimsical or fantasy, likely dreamed up by people who have read too much science fiction as children.
This "reality" is further validated by the people they choose to keep around them, the community they live in, and oftentimes the country as well. For example, their reality is validated by a hunk of rock bearing the Ten Commandments erected in a public courthouse. It is validated by Christmas and Easter being public holidays. It is validated every time a politician intones that America is a "Christian nation." And what reason would they possibly have to question those assumptions?
When these validation mechanisms are questioned, oftentimes those who hold their version of reality as dear, will do some very strange things, sometimes even against the tenets of their own religion, to keep up the perception. After all, questioning core beliefs can be quite frightening. While this may seem like throwing the baby out with the bath water, it often happens when the validation becomes more important than the actual message on which the person's reality is based.
So why am I a Wiccan? Because I saw the fnords. My core value system was called into question. Alternate information was presented in a form that triggered a deep contemplative response. In my case, the information was presented, unwittingly, by a Sunday School teacher when I was 7. Once the process was begun, there was no going back. The comfortable little cubbyhole called Christianity no longer worked on most levels. There were too many holes, too many contradictions, my foot outgrew the shoe. But there were some parts that DID work, and I chose to keep those parts as my personal reality, and eschew the rest.
But that still doesn't quite resolve why I am a Wiccan. It explains why I am not a Christian, but that is not the whole of the story. Once one sees the fnords, they are everywhere. They are in all religions, in the holy teachings, in the books, in the clergy, everywhere. But unlike other religions that call those who see fnords "heretics" or "unbelievers" or burn them at the stake, Wicca EMBRACES them. The religion REQUIRES you to think them through, not to accept discongruity on "faith." It provises a skeletal structure on which you fashion the flesh of your own reality, complete with your own fnords. And so long you accept the skeleton as your foundation, your reality can look almost any way you desire.
Unlike other religions, you must THINK and LEARN and accept or reject pieces before they are grafted to the skeleton of your reality. And if a piece no longer fits, you can refashion it, so long as the skeleton remains whole.
This is not to say that the skeleton itself cannot be changed. It can. It just then is not Wicca, but something else. The point is that to be a Wiccan you must examine your core, do research, create writings, learn lessons, and formulate your OWN ideas of right, wrong, and what's in the middle. Most Wiccans know that shades of grey exist everywhere, and that life cannot be dictated by stone tablets, unchanging books, or because someone else said so. And THAT is why I am a Wiccan.