Speaking to your point, some speculation follows:
We'll start with the stereotype/assumption that many engineers prefer stability and consistency in many aspects of their environments.
April Fool's day upends consistency in a significant fraction of consistent events and assumptions. The corollary is that the only consistency introduced on this day alone is the inconsistencies introduced elsewhere, and even this isn't certain given that not everyone participates.
Therefore, if many engineers strongly prefer consistency and April Fool's Day disrupts consistency, it potentially stands to reason that many engineers do not prefer to be involved in/with April Fool's Day.
...I'm less of an engineer and more of a manager now, so I've come to appreciate the gags, but man was there a time when I didn't. lol
