Apple was able to manage this with a much bigger market and a lot more apps (when transitioning to OS X), so while it would be hard, I think Palm could have been able to do that as well.
But as you say, the company structure, market position and a lot more worked against them (same thing with Nokia and Symbian).
But as you say, the company structure, market position and a lot more worked against them (same thing with Nokia and Symbian).