If this were really the justification, there are almost always better ways to do it. ("If you're wondering about X, see section N". Or just link to it.) Like

If this were really the justification, there are almost always better ways to do it. ("If you're wondering about X, see section N". Or just link to it.) Like other dark patterns, there times when this sort of thing can make sense, but in practice it's usually done (consciously or not) to get the reader to read more than they would otherwise.