People are vaguely aware that engineers design and oversee the complex technologies on which we all depend, from subways to satellites. Most laymen can't fathom anything more specific than that, however. Now he fibs that he writes children's books, which acquaintances can comprehend and appreciate. Engaging in activities that the larger community doesn't fully understand, being different and apart from others in some ways, thought of as uppity, and displaying superior abilities in certain areas where the masses are dependent on you constitutes a recipe for resentment. Indeed, non-techies react with belittling humor and name calling.
People casually stigmatize engineers as nerds and geeks.
Crichton probably expressed a subconscious wish of many readers to put engineers down and show themselves superior. As a form of dishonesty and disrespect, stereotyping people is never harmless. Although discrimination might not bother most engineers, we all lose whenever such ignorance is a determining factor in controversy. One of my roundtable participants, Art, pointed out that we learn much about occupations from fiction, and rare is the book, movie, or TV show that features engineers. So, Michael, in the future you might use your writing talent not to spread prejudice against engineers but to fight it.