That is strange. Even as a Swede I would probably value a Billy more if it came pre assambled, so I was not made actively aware of low quality materials and holes drilled in not-quite-the-right places.
Maybe a cultural thing. I always got the impression IKEA is more respected in other countries, while in Sweden it is seen as cheap furniture owned by everyone.
I think that's true. But, in addition, in the US going to an Ikea is usually a bit of an expedition as there aren't that many stores. The stores themselves make things a bit of an event because they're different from the norm, have a fairly nice cafeteria, etc. Add it up and there's a certain aura to Ikea furniture that wouldn't exist if you picked up the exact same box at the local Walmart.
A standard of living thing, you Swedes are richer than almost everyone else.
At some point, McDonalds here (ass end of Eastern Europe) was a place where well-dressed grandparents took their well-dressed kids on Sunday lunches.
Right now Ikea is something people aspire to, as a mark of getting into the middle class. There's A LOT of cheaper, crapier local stuff, with bleached pine wood you can leave a visible dent on if you drop a plate on. (Funny thing is, many of the same furniture factories also work for Ikea.)
Maybe a cultural thing. I always got the impression IKEA is more respected in other countries, while in Sweden it is seen as cheap furniture owned by everyone.