Starting with the Wii Nintendo has significantly loosened their requirements for publishing games on their platforms. The Wii SDK is much cheaper (almost an order of magnitude) than either the Xbox or PS3 dev kits, the from what I can tell approval processes are far less onerous.
What has resulted? A deluge of crap. The amount of cheap shovelware games for the Wii boggles the mind, and dilutes the Wii brand significantly. It gets so bad that even non-gamer grandmas have noticed.
In comparison, Sony and MS are riding high, they have a gigantic amount of 3rd party support, people are willing to pay their ticket price for entry to the platform, and willing to put up with a lot more content restrictions (e.g., no free DLC, extensive multiplay/connectivity requirements even for singleplayer games)
There's a fine line to be walked here, and I'm not sure if Android has the model right either.