I see some reasoning in it when thinking about apps. Small individual developers have very limited resources. Developing their app for a bunch of different platforms might be beyond their means or just not seem worth it to them, so they just develop for the biggest or biggest 2-3 platforms. People might avoid buying a WebOS device specifically because of the small number of apps. The Iphone app store has over 100,000 apps, the Android market has over 30,000, and the WebOS store has something like 1,000.
That said, getting the WebOS onto a much larger number of devices would make the OS more enticing for developers to commit to. That does seem like a really good move for Palm. How many manufacturers would pay to license WebOS when they could use Android for free though?