Some of these posters have probably not yet had the necessary courses in basic electronics, but have a keen interest and are reaching well beyond there level to try these projects. Others are older and are comming late to this field with little or no formal education relevant to electronics. These questions are not dumb to them and serve as an indicator of what books or courses they need to master to function in this field.
I have a Friend that is a cutting edge research scientist in heart desease and have sat in on a few of her lectures and presentations. It is a very humbling experience to feel so ignorant and lost when all those around you understand the presented subject matter. When her husband and I talk "engineering" she leaves because she cannot understand us.
Remember "the guy that asks dumb questions today" may well be the wise old timer in 35 years. Regards Terry