You raise an interesting point. I've always felt myself to be a relatively sensitive/intuitive person but I've also met people who seem way more or less intuitive, which leads me to wonder if it's something innate or something people can develop but your line of reasoning makes me wonder if it isn't possible for people to be sensitive to different things?

For example, the person who taught me how to meditate once admitted to me that he doesn't have very vivid dreams but he always kind of figured his overly-vivid meditation made up for it. Maybe he's more sensitive to conscious stimuli whereas others may be more sensitive to the unconscious.