goyo

I can give you several reasons:

1. Many site users have fixed width sites and they would like ALL content to fit within the dimensions of the site.
2. Regardless of how big a users monitor is, users will always come up with images SO LARGE that they won't fit in any monitor
3. Regardless on your opinion on the issue, vbulletin provides this functionality so unless you want to hear about it regularly from here until the end of time, you'll need to address the issue.

And as I stated before, my #1 biggest complaint from my users after migrating from Vbulletin is the lack of options in photo attachment handling. And this is just one site in hundreds or thousands of sites that could end up moving to IPB. Why would you not add the settings many of your customers need? Seems pretty simple to me.

Fundamentally, they are quite different. CCS will be an application for IP.Board, while Dynamic was a stand-a-lone application. CCS also is purely for content (at least in this 1.0 version) while Dynamic had a myriad of other features which are not needed as they are already in IP.Board (for example, Dynamic had Personal Conversations, which is now in IP.Board 3).
But of course, there are similarities in that they are both content creation systems :)