Well, i think there's a number of things that contribute to the Wii "dislike".
A lot of the developers actually want to make graphically more intensive games that the Wii is capable of.
A number of devs want to make money with their engine investment, so even when you could make more money with a Wii game, they still choose to go PS360, so that the engine investments wouldn't be count as loss.
PS3 and 360 still has bigger combined userbase that the Wii has. And cheap ports/unified developement cuts down costs per version.
Well made sequels to popular games sell well on all platforms.
If you are able to create a new IP that is quality made and loved by public, it will sell huge on PS360 (think about Gears of War).
Bad game is easier to hide behind flashy visuals.
PS360 userbase is heavily geared towards certain genres, which makes flashy games in the genre easy to sell.
The publishers/devs still don't know what kind of games to make for Wii.
Ei Kiinasti.
Eikä Japanisti.
Vaan pannaan jalalla koreasti.
Nintendo games sell only on Nintendo system.