Mountains Of The Murgha Zerin

I am a bit perplexed with this book. I didn't find it particularly readable, but I can't establish why.

Published in 1972, it is the story of a mother and son who travel quite extensively in mountainous Pakistan - in the zone between the Hindu Kush and the Karakoram. They travel hard, and into an interesting area, meet interesting people. The book contains a good background history of the area, and the persons they encounter.

It isn't particularly funny, it isn't particularly light reading, but it comes across as legitimate, honest, and realistic. The author is a likeable Scotswoman, and her son similarly likeable.
I just don't really see why this isn't excellent - almost compulsive reading (for me) - it is even published by the Travel Book Club - which recommends it to me as suitable to purchase without researching.

It just seems so put-down-able and doesn't entice me to pick it up again!
I took me a long time and a lot of perseverance to read its mere 237 pages. But I still enjoyed the content.

So leaving me confused as to why, I am giving it a 3 star rating!