For me to think in this way, is highly disturbing, because i always felt everything i was going through a 'necessary' to clear myself of 'baggage', heal & become more aware & more my authentic self which i hoped would have me living a 'nicer' more connected & fullfilling life
I can't know why this author decided this was unnecessary, and I agree that it's not how I'd think of it, but I have an idea of why he might think this way-
I think there is a tendency for organized thought systems to require suffering as a neccessity, and I think this is also nonproductive- I have always believed that, whether something is perceived as good or bad, if it leads you to become a better 'person/ego' then it is necessary- but in retrospect sometimes this gets extrapolated in a system and the thought becomes "it is necessary to experience negativity to grow", and then it becomes true because thought systems take it on as truth (in a LoA or egregor kind of way).
So I think it would be good for spiritual systems to stop being of the thought that suffering is necessary, and at the same time realize that anything that has happened was necessary for that person, but their experience can teach others and so it is not necessary for 'everyone' to go through it.
I'm not sure if this is clear, but someone I used to know used to say that people forget all about Grace, and that's a shame.