Steve Jobs recently outlined the Applethink on Flash, giving six reasons why they refuse to support it on the Touch devices. Some of the arguments are weaker than others — I mean, come on, Flash isn’t open but it’s certainly more open than Apple’s touch devices have been.

But Jobs really only had to make one argument: even if Flash worked as intended on Touch devices, it still wouldn’t “work.”

Flash was designed for PCs using mice, not for touch screens using fingers. For example, many Flash websites rely on “rollovers”, which pop up menus or other elements when the mouse arrow hovers over a specific spot. Apple’s revolutionary multi-touch interface doesn’t use a mouse, and there is no concept of a rollover. Most Flash websites will need to be rewritten to support touch-based devices. Steve Jobs, Thoughts on Flash

Flash applications are commonly very sensitive to the location and behavior of the mouse pointer. But since Touch devices lack this pointer those applications won’t work as planned. That includes any non-trivial Flash game and many Flash apps.

The lack of an integrated keyboard also makes using Flash very difficult. The pop-up keyboard will likely obscure large portions of the Flash you’re trying to interact with. There are ways around that to be sure, but when I think of what either Adobe or Apple would have to do just to get some half-measures in place, well … there’s a reason I’m up at four in the morning.

Even advertising would be hideously broken — no more screen takeovers when you rolled the pointer over the wrong spot. Because you can’t roll over.

Hey, wait — that’s a benefit.

The simple fact is that most Flash apps will not work without a keyboard and a mouse. An iPad user might have an external keyboard, but probably not. The iPhone has neither. Except for simple Flash video players, Flash is almost guaranteed to fail even if it loads and displays correctly.

And who would get blamed for that? Most likely Apple.

Apple has tried very hard with both devices to convince people to use a different kind of user interface. Fans of the iPad say the device just “disappears.” That’s because much of what people experience on Touch devices was designed for touch — the exception being websites, which have tended to be quite simple.

But if you’re constantly being faced with things just out of reach that appear to function but don’t because you don’t have a mouse or a keyboard, well, you’re going to keep thinking about how you need a mouse or a keyboard. Suddenly the iPad’s touch interface are in the way.

That’s the last thing Apple wants. Better to have Flash fail completely every time than constantly hammer users with inaccessible content: “No, we don’t support Flash.” And that’s the end of it.