I've read a lot about modafinil and I think your observations are selection bias. It may improve focus more than caffeine but not like amphetamines or other drugs used to treat ADHD. Judgement may be impaired when taking any stimulant. If it's something you're aware of it's not hard to work around.
I've heard a fair number of people report getting no effect, and recall reading somewhere that there's a gene which separates modafinil responders from non-responders. It's just that non-responders tend not to talk about it, since it's much less interesting in that case.
Everyone talks of extreme focus, but perhaps a loss of judgement about what tasks are actually important.
I don't have any particular conclusions about that - I just find it really interesting.