*randomly jumping in*
I think a well done UI adds value to a platform as a whole. If the platform usable and it has advantages, developers will be naturally attracted to a platform. "Everyday" users, however, probably will not. They *need* the whiz-bang to validate their purchase price and get the "experience".
Since a lack of these "whiz-bang" effects/UI enhancements of other sorts leads to a lack of users/smaller user base, fewer developers dedicate time to the platform. I bought my n810 because it was purported to have an excellent internet experience, including flash, etc. Day by day, those technologies are moving forward, and we have only some efforts to stay with the times. If we had a dedicated developer base serving millions of users, we would have a much better chance at having device that keeps up with technological standards. I think the smart play for Nokia is to add whiz-bang effects to the OS and add a monetization scheme (read: application catalog) to attract more "closed-source-monetizing" developers (I know, I know - this is pretty vilified in these forums) and (more important) more open-source developers to move the platform forward.

Summary:
No whiz bang/UI optimizations = fewer users = fewer developers = stagnant platform
whiz bang/UI optimizations = more users = more developers = developing platform

Ask yourself:
Why is it that every other site these days has an iPhone/iPod touch (free) application / website modification to suit the device?
Answer: Everyday users like the experience = bigger user base; Websites/companies recognize the need to reach out to those users and are willing to take the time to develop applications in-house/outsource development to get a solution in place for those mobile users.

Just my .02 cents.