You'd have a very hard time convincing me that most business users - from an accountant, to an attorney, to a physician, to a marketing weasel - really "needs" to access a hierarchical file system.
Lets leave aside your (not very subtle) digs at the iPad for being a "content consumption" device, suitable only for "grandmas" for a second. And take a look at our own, human, evolutionary history.
At one point, our biological pre-human ancestors had tails. And modern humans don't. Now, you could make an argument that, every once in a while, some people might find it useful to have a tail. Washing dishes would, I guess, be little easier with an extra appendage. And certainly gymnastics events would be a little more exciting. But having a tail comes at a cost: You would need to provide extra bloodsupply and calories to support a tail. And tails would make it very difficult to sit comfortably, and they'd probably always be getting (painfully) caught in elevator doors and toilet seats. Bottom line: While some people, some of the time would find a tail useful - its on balance much better that humans lost our tails.
So too with Flash. It might sometimes be useful to have. But it comes at a tremendous cost: it sucks battery and processor cycles. Its riddled with security and privacy flaws. It has a host of interface problems (no "mouseover event on a tablet). So - from a computer-evolutionary perspective: Flash is a like a tail. An unneccessary appendage we'd all, on balance, be better off without.
After looking behind me to ensure I didn't have a tail
As for Flash, I can't quote you figures or numbers and I'll readily admit that. But I've used PC's with flash all my life, and most recently I have an Android phone and I've never seen this "tremendous cost" that Flash comes with. But the fact of the matter is that it's an integral part of the internet experience and to not have it is to not offer the internet in its entirety, at least for myself as I'm sure users will jump right in how they never ever encounter a flash site in their daily browsing. In your analogy of a tail being a vestigial appendage if you use the tail for some function then it isn't necessarily vestigial, even if it's only a small percentage of what you use your other appendages for. Flash isn't vestigial because it's not going anywhere, it's not going out of business every other smartphone and computer platform embraces them, and it's something that many people encounter on a very regular basis in their innocent web browsing. Does Apple really think they are going to ride in on a white horse and eradicate Flash when they are the only ones who are shunning it? Well excuse me if they want to attack windmills Don Quixote style, but MY reality today is that I need flash for my internet experience, and that's something that other companies understand. It's even a marketing point, the Playbook and xoom have both used it in their advertising.
By the way I never said the ipad was "only" for grandmas, and I've already admitted to it being a poor analogy. But whatever analogy you want to use for your everyday non tech layman is really what I meant, and that IS Apple's bread and butter when it comes to the ipad. Of course very tech people also buy the ipad, but the masses that purchase it are not necessarily network engineers or software programmers. Once again I didn't mean Grandma as a slight, just a crappy analogy, once again I own an ipad myself and don't sit up at night in an attempt to come up with better ways to insult myself.
Kind of summarily, I think some are taking my points too literally and not so much figuratively as they are meant to be. Do I really expect the ipad3 to sprout a keyboard and be able to run microsoft spreadsheets? No, but I do expect either a) some kind of evolution which would bring the ipad to more business type functions, or b) Apple will continue to market the ipad as a 3rd device for content consumption and leave their iMacs and Macbooks as the serious business machines. It's interesting to note that any evolution such as this will first have to be weighed in as a business decision and not an altruistic gift to humankind, despite the beliefs of some.