I've been thinking about this, and it's not the same. Take for example Debian or Ubuntu. Pushing stuff into their equivalent of extras is far, FAR more difficult than maemo, however, their repositories contain 99% of packages a user will ever need. Hence, repositories are not a big deal, most users will never find out what they are and what trouble they might cause.

On ther hand, in maemo land, until the recent extras consolidation effort, using a hundred unsynchronized and unrelated repositories was the norm and it was already turning into a mess.

To recap my opinion - for a power user, who knows what's he doing, private repos are ok. For a newbie, it's a disaster as he won't know what hit him when things go south. That's why (from a user's perspective), private repos should not be the endorsed norm, but the (understandable and justified) exception - and that's why we need a strong (and full) extras