Maybe because instruction manuals start off with so many pages of warnings, cautions, and other junk that nobody reads anyway. Or were you talking about instructions on this forum?
There are some people who are "instruction-challenged." Someone whom I am very close to has an immediate mental block when presented with "Step one:". Others feel so confident that they plow ahead without looking at the instructions, anticipating that they can either intuitively master the device/software/project/etc or learn on the fly.
You do see qustions on usergroups that are absolutely elementry. Some impatient experts on these groups respond with putdowns or sarcasm, and some respond with simply typing RTFM (READ THE F---- MANUAL.) I've refrained from asking software questions on some usergroups for this very reason. No pleasure to be flamed for an honest request. This Forum has the very kind culture of responding to the even the most basic newbie questions.