I've got hundreds of hours in Wii Sports / Resort, and Wii Fit. I'm already a big fan of those games, and I think they have plenty of merit.
As for value, I've paid full price for Tetris a bunch of times too, which is often considered as a low value game by many.
I also think Pilotwings is great, is well designed, and has plenty of content. It's the first thorough use of the island, expanding upon the Airplane game nicely. I thought it was going to be poor (especially based upon reviews), but came away very impressed.
It's fair enough that for many the perception of the content is different, however. It certainly seems like a cheap 'demo' in terms of the island being recycled, and the use of Miis devalues the product. I wonder whether Mii based games are regarded as 'free' or low value now.
It's very interesting how certain games and genres go through phases in terms of regarded value. Street Fighter 4, for example, is similar in so much that it's only as good as the time you invest.