I love the books, I have read them all to my kids, and I agree that I think the article takes its thesis too far.
The books are strange tales. They have dark undertones. And sometimes the adults take actions that only someone with life experience would really understand (e.g. Moominpappa wanting to suddenly upend everything in the families life and move to an isolated island). But, my kids mostly pick up on the adventure and the friendships.
I feel that the Moomins are like most media that is enjoyable by both children and parents in this way (e.g. Bluey, Pixar films, etc.).
Another way to view it is a series that accompanies a child to young adult years. (It took me a few years to get through the series inbetween other books. I assume many bedtime reads for the first few, and independent reading for later ones). What starts as fantastical and whimsical, indeed becomes more somber and concerning interpersonal dynamics, especially those within Moomin family and those around them. "Moominpapa at Sea" is probably most relatable to adult readers. The underlying message of family unity, finding ways to cope with certain events, parenting styles, need to break routines (picnics), unrequited crushes.
Moominland Midwinter is interesting character study too, with sporty "artistic" coded Hemulen proving too much for most of the cast to handle, the forgetful grandpa. Perhaps the message was it is okay to not be friends with everyone as it is a bother.
Compare it to "Finn Family Moomintroll" which is just a constantly stacking ridiculous lighthearted escapade with a few more mature jokes mixed in.
Based on your experience, what age do you think is ideal for introducing the books to kids?
I started reading the novel stories when the kids were 3yo and 6yo. Both love them. My 3yo for the drawings mostly.
There are a number of excellent picture book adaptations of stories that have been published too. But, we read those afterwards and obviously they aren’t as enjoyable to me.
Because this is HN: My tradition is to use my Inkpalm 5 and read them with the lights out at bedtime- we pass the reader around to look at pictures.
Not the previous poster, but based on my own experience as a kid and also my kids I'd say age 5 is perfectly good age to introduce the books.
As an adult you pick up on some the more serious themes but as a kid you just enjoy the story and the bit of danger and overcoming and the overall wholesomeness.
Mine started 5/6, but the more recent books are made for kids. The earlier newspaper cartoons are not. Same with TV, the later Japanese/Dutch produced TV series is lovely. The earlier TV series (there are several) are dark as the cupboard under the stairs and the Groke goes postal killing everything in one.
[0] https://www.moomin.com/en/blog/moomin-tv-animations/
While all the books have both humour and darkness, the early books are more whimsical and playful while the later books are more about loneliness, alienation, and loss.